Merge isolates to bleeding_edge.

src/objects.cc

Index: src/objects.cc
===================================================================
--- src/objects.cc	(revision 7267)
+++ src/objects.cc	(working copy)
@@ -51,7 +51,6 @@
 #include "disassembler.h"
 #endif
 
-
 namespace v8 {
 namespace internal {
 
@@ -64,7 +63,8 @@
 MUST_USE_RESULT static MaybeObject* CreateJSValue(JSFunction* constructor,
                                                   Object* value) {
   Object* result;
-  { MaybeObject* maybe_result = Heap::AllocateJSObject(constructor);
+  { MaybeObject* maybe_result =
+        constructor->GetHeap()->AllocateJSObject(constructor);
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
   JSValue::cast(result)->set_value(value);
@@ -86,14 +86,19 @@
 
 
 MaybeObject* Object::ToObject() {
-  Context* global_context = Top::context()->global_context();
   if (IsJSObject()) {
     return this;
   } else if (IsNumber()) {
+    Isolate* isolate = Isolate::Current();
+    Context* global_context = isolate->context()->global_context();
     return CreateJSValue(global_context->number_function(), this);
   } else if (IsBoolean()) {
+    Isolate* isolate = HeapObject::cast(this)->GetIsolate();
+    Context* global_context = isolate->context()->global_context();
     return CreateJSValue(global_context->boolean_function(), this);
   } else if (IsString()) {
+    Isolate* isolate = HeapObject::cast(this)->GetIsolate();
+    Context* global_context = isolate->context()->global_context();
     return CreateJSValue(global_context->string_function(), this);
   }
 
@@ -103,35 +108,43 @@
 
 
 Object* Object::ToBoolean() {
-  if (IsTrue()) return Heap::true_value();
-  if (IsFalse()) return Heap::false_value();
+  if (IsTrue()) return this;
+  if (IsFalse()) return this;
   if (IsSmi()) {
-    return Heap::ToBoolean(Smi::cast(this)->value() != 0);
+    return Isolate::Current()->heap()->ToBoolean(Smi::cast(this)->value() != 0);
   }
-  if (IsUndefined() || IsNull()) return Heap::false_value();
+  if (IsUndefined() || IsNull()) {
+    return HeapObject::cast(this)->GetHeap()->false_value();
+  }
   // Undetectable object is false
   if (IsUndetectableObject()) {
-    return Heap::false_value();
+    return HeapObject::cast(this)->GetHeap()->false_value();
   }
   if (IsString()) {
-    return Heap::ToBoolean(String::cast(this)->length() != 0);
+    return HeapObject::cast(this)->GetHeap()->ToBoolean(
+        String::cast(this)->length() != 0);
   }
   if (IsHeapNumber()) {
     return HeapNumber::cast(this)->HeapNumberToBoolean();
   }
-  return Heap::true_value();
+  return Isolate::Current()->heap()->true_value();
 }
 
 
 void Object::Lookup(String* name, LookupResult* result) {
   if (IsJSObject()) return JSObject::cast(this)->Lookup(name, result);
   Object* holder = NULL;
-  Context* global_context = Top::context()->global_context();
   if (IsString()) {
+    Heap* heap = HeapObject::cast(this)->GetHeap();
+    Context* global_context = heap->isolate()->context()->global_context();
     holder = global_context->string_function()->instance_prototype();
   } else if (IsNumber()) {
+    Heap* heap = Isolate::Current()->heap();
+    Context* global_context = heap->isolate()->context()->global_context();
     holder = global_context->number_function()->instance_prototype();
   } else if (IsBoolean()) {
+    Heap* heap = HeapObject::cast(this)->GetHeap();
+    Context* global_context = heap->isolate()->context()->global_context();
     holder = global_context->boolean_function()->instance_prototype();
   }
   ASSERT(holder != NULL);  // Cannot handle null or undefined.
@@ -154,6 +167,7 @@
                                              Object* structure,
                                              String* name,
                                              Object* holder) {
+  Isolate* isolate = name->GetIsolate();
   // To accommodate both the old and the new api we switch on the
   // data structure used to store the callbacks.  Eventually proxy
   // callbacks should be phased out.
@@ -161,7 +175,7 @@
     AccessorDescriptor* callback =
         reinterpret_cast<AccessorDescriptor*>(Proxy::cast(structure)->proxy());
     MaybeObject* value = (callback->getter)(receiver, callback->data);
-    RETURN_IF_SCHEDULED_EXCEPTION();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
     return value;
   }
 
@@ -174,17 +188,19 @@
     JSObject* self = JSObject::cast(receiver);
     JSObject* holder_handle = JSObject::cast(holder);
     Handle<String> key(name);
-    LOG(ApiNamedPropertyAccess("load", self, name));
-    CustomArguments args(data->data(), self, holder_handle);
+    LOG(isolate, ApiNamedPropertyAccess("load", self, name));
+    CustomArguments args(isolate, data->data(), self, holder_handle);
     v8::AccessorInfo info(args.end());
     v8::Handle<v8::Value> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       result = call_fun(v8::Utils::ToLocal(key), info);
     }
-    RETURN_IF_SCHEDULED_EXCEPTION();
-    if (result.IsEmpty()) return Heap::undefined_value();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
+    if (result.IsEmpty()) {
+      return isolate->heap()->undefined_value();
+    }
     return *v8::Utils::OpenHandle(*result);
   }
 
@@ -196,7 +212,7 @@
                                                   JSFunction::cast(getter));
     }
     // Getter is not a function.
-    return Heap::undefined_value();
+    return isolate->heap()->undefined_value();
   }
 
   UNREACHABLE();
@@ -210,9 +226,10 @@
   Handle<JSFunction> fun(JSFunction::cast(getter));
   Handle<Object> self(receiver);
 #ifdef ENABLE_DEBUGGER_SUPPORT
+  Debug* debug = fun->GetHeap()->isolate()->debug();
   // Handle stepping into a getter if step into is active.
-  if (Debug::StepInActive()) {
-    Debug::HandleStepIn(fun, Handle<Object>::null(), 0, false);
+  if (debug->StepInActive()) {
+    debug->HandleStepIn(fun, Handle<Object>::null(), 0, false);
   }
 #endif
   bool has_pending_exception;
@@ -230,6 +247,7 @@
     LookupResult* result,
     String* name,
     PropertyAttributes* attributes) {
+  Heap* heap = name->GetHeap();
   if (result->IsProperty()) {
     switch (result->type()) {
       case CALLBACKS: {
@@ -281,8 +299,8 @@
 
   // No accessible property found.
   *attributes = ABSENT;
-  Top::ReportFailedAccessCheck(this, v8::ACCESS_GET);
-  return Heap::undefined_value();
+  heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_GET);
+  return heap->undefined_value();
 }
 
 
@@ -291,6 +309,7 @@
     LookupResult* result,
     String* name,
     bool continue_search) {
+  Heap* heap = name->GetHeap();
   if (result->IsProperty()) {
     switch (result->type()) {
       case CALLBACKS: {
@@ -344,7 +363,7 @@
     }
   }
 
-  Top::ReportFailedAccessCheck(this, v8::ACCESS_HAS);
+  heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_HAS);
   return ABSENT;
 }
 
@@ -378,16 +397,14 @@
                                              Object* value,
                                              PropertyDetails details) {
   ASSERT(!HasFastProperties());
+  Heap* heap = name->GetHeap();
   int entry = property_dictionary()->FindEntry(name);
   if (entry == StringDictionary::kNotFound) {
     Object* store_value = value;
     if (IsGlobalObject()) {
-      { MaybeObject* maybe_store_value =
-            Heap::AllocateJSGlobalPropertyCell(value);
-        if (!maybe_store_value->ToObject(&store_value)) {
-          return maybe_store_value;
-        }
-      }
+      MaybeObject* maybe_store_value =
+          heap->AllocateJSGlobalPropertyCell(value);
+      if (!maybe_store_value->ToObject(&store_value)) return maybe_store_value;
     }
     Object* dict;
     { MaybeObject* maybe_dict =
@@ -416,6 +433,7 @@
 
 MaybeObject* JSObject::DeleteNormalizedProperty(String* name, DeleteMode mode) {
   ASSERT(!HasFastProperties());
+  Heap* heap = GetHeap();
   StringDictionary* dictionary = property_dictionary();
   int entry = dictionary->FindEntry(name);
   if (entry != StringDictionary::kNotFound) {
@@ -423,7 +441,7 @@
     if (IsGlobalObject()) {
       PropertyDetails details = dictionary->DetailsAt(entry);
       if (details.IsDontDelete()) {
-        if (mode != FORCE_DELETION) return Heap::false_value();
+        if (mode != FORCE_DELETION) return heap->false_value();
         // When forced to delete global properties, we have to make a
         // map change to invalidate any ICs that think they can load
         // from the DontDelete cell without checking if it contains
@@ -436,13 +454,13 @@
       }
       JSGlobalPropertyCell* cell =
           JSGlobalPropertyCell::cast(dictionary->ValueAt(entry));
-      cell->set_value(Heap::the_hole_value());
+      cell->set_value(heap->the_hole_value());
       dictionary->DetailsAtPut(entry, details.AsDeleted());
     } else {
       return dictionary->DeleteProperty(entry, mode);
     }
   }
-  return Heap::true_value();
+  return heap->true_value();
 }
 
 
@@ -468,6 +486,7 @@
   // Make sure that the top context does not change when doing
   // callbacks or interceptor calls.
   AssertNoContextChange ncc;
+  Heap* heap = name->GetHeap();
 
   // Traverse the prototype chain from the current object (this) to
   // the holder and check for access rights. This avoid traversing the
@@ -475,7 +494,7 @@
   // holder will always be the interceptor holder and the search may
   // only continue with a current object just after the interceptor
   // holder in the prototype chain.
-  Object* last = result->IsProperty() ? result->holder() : Heap::null_value();
+  Object* last = result->IsProperty() ? result->holder() : heap->null_value();
   for (Object* current = this; true; current = current->GetPrototype()) {
     if (current->IsAccessCheckNeeded()) {
       // Check if we're allowed to read from the current object. Note
@@ -483,7 +502,7 @@
       // property from the current object, we still check that we have
       // access to it.
       JSObject* checked = JSObject::cast(current);
-      if (!Top::MayNamedAccess(checked, name, v8::ACCESS_GET)) {
+      if (!heap->isolate()->MayNamedAccess(checked, name, v8::ACCESS_GET)) {
         return checked->GetPropertyWithFailedAccessCheck(receiver,
                                                          result,
                                                          name,
@@ -498,7 +517,7 @@
 
   if (!result->IsProperty()) {
     *attributes = ABSENT;
-    return Heap::undefined_value();
+    return heap->undefined_value();
   }
   *attributes = result->GetAttributes();
   Object* value;
@@ -507,11 +526,11 @@
     case NORMAL:
       value = holder->GetNormalizedProperty(result);
       ASSERT(!value->IsTheHole() || result->IsReadOnly());
-      return value->IsTheHole() ? Heap::undefined_value() : value;
+      return value->IsTheHole() ? heap->undefined_value() : value;
     case FIELD:
       value = holder->FastPropertyAt(result->GetFieldIndex());
       ASSERT(!value->IsTheHole() || result->IsReadOnly());
-      return value->IsTheHole() ? Heap::undefined_value() : value;
+      return value->IsTheHole() ? heap->undefined_value() : value;
     case CONSTANT_FUNCTION:
       return result->GetConstantFunction();
     case CALLBACKS:
@@ -536,7 +555,7 @@
   }
 
   Object* holder = NULL;
-  Context* global_context = Top::context()->global_context();
+  Context* global_context = Isolate::Current()->context()->global_context();
   if (IsString()) {
     holder = global_context->string_function()->instance_prototype();
   } else if (IsNumber()) {
@@ -546,7 +565,7 @@
   } else {
     // Undefined and null have no indexed properties.
     ASSERT(IsUndefined() || IsNull());
-    return Heap::undefined_value();
+    return HEAP->undefined_value();
   }
 
   return JSObject::cast(holder)->GetElementWithReceiver(receiver, index);
@@ -556,14 +575,15 @@
 Object* Object::GetPrototype() {
   // The object is either a number, a string, a boolean, or a real JS object.
   if (IsJSObject()) return JSObject::cast(this)->map()->prototype();
-  Context* context = Top::context()->global_context();
+  Heap* heap = Isolate::Current()->heap();
+  Context* context = heap->isolate()->context()->global_context();
 
   if (IsNumber()) return context->number_function()->instance_prototype();
   if (IsString()) return context->string_function()->instance_prototype();
   if (IsBoolean()) {
     return context->boolean_function()->instance_prototype();
   } else {
-    return Heap::null_value();
+    return heap->null_value();
   }
 }
 
@@ -637,9 +657,10 @@
   // allowed.  This is to avoid an assertion failure when allocating.
   // Flattening strings is the only case where we always allow
   // allocation because no GC is performed if the allocation fails.
-  if (!Heap::IsAllocationAllowed()) return this;
+  if (!HEAP->IsAllocationAllowed()) return this;
 #endif
 
+  Heap* heap = GetHeap();
   switch (StringShape(this).representation_tag()) {
     case kConsStringTag: {
       ConsString* cs = ConsString::cast(this);
@@ -649,12 +670,12 @@
       // There's little point in putting the flat string in new space if the
       // cons string is in old space.  It can never get GCed until there is
       // an old space GC.
-      PretenureFlag tenure = Heap::InNewSpace(this) ? pretenure : TENURED;
+      PretenureFlag tenure = heap->InNewSpace(this) ? pretenure : TENURED;
       int len = length();
       Object* object;
       String* result;
       if (IsAsciiRepresentation()) {
-        { MaybeObject* maybe_object = Heap::AllocateRawAsciiString(len, tenure);
+        { MaybeObject* maybe_object = heap->AllocateRawAsciiString(len, tenure);
           if (!maybe_object->ToObject(&object)) return maybe_object;
         }
         result = String::cast(object);
@@ -669,7 +690,7 @@
                     len - first_length);
       } else {
         { MaybeObject* maybe_object =
-              Heap::AllocateRawTwoByteString(len, tenure);
+              heap->AllocateRawTwoByteString(len, tenure);
           if (!maybe_object->ToObject(&object)) return maybe_object;
         }
         result = String::cast(object);
@@ -684,7 +705,7 @@
                     len - first_length);
       }
       cs->set_first(result);
-      cs->set_second(Heap::empty_string());
+      cs->set_second(heap->empty_string());
       return result;
     }
     default:
@@ -708,7 +729,7 @@
                   resource->length() * sizeof(smart_chars[0])) == 0);
   }
 #endif  // DEBUG
-
+  Heap* heap = GetHeap();
   int size = this->Size();  // Byte size of the original string.
   if (size < ExternalString::kSize) {
     // The string is too small to fit an external String in its place. This can
@@ -724,8 +745,8 @@
   // Morph the object to an external string by adjusting the map and
   // reinitializing the fields.
   this->set_map(is_ascii ?
-                Heap::external_string_with_ascii_data_map() :
-                Heap::external_string_map());
+                heap->external_string_with_ascii_data_map() :
+                heap->external_string_map());
   ExternalTwoByteString* self = ExternalTwoByteString::cast(this);
   self->set_length(length);
   self->set_hash_field(hash_field);
@@ -736,13 +757,13 @@
     self->Hash();  // Force regeneration of the hash value.
     // Now morph this external string into a external symbol.
     this->set_map(is_ascii ?
-                  Heap::external_symbol_with_ascii_data_map() :
-                  Heap::external_symbol_map());
+                  heap->external_symbol_with_ascii_data_map() :
+                  heap->external_symbol_map());
   }
 
   // Fill the remainder of the string with dead wood.
   int new_size = this->Size();  // Byte size of the external String object.
-  Heap::CreateFillerObjectAt(this->address() + new_size, size - new_size);
+  heap->CreateFillerObjectAt(this->address() + new_size, size - new_size);
   return true;
 }
 
@@ -759,7 +780,7 @@
                   resource->length() * sizeof(smart_chars[0])) == 0);
   }
 #endif  // DEBUG
-
+  Heap* heap = GetHeap();
   int size = this->Size();  // Byte size of the original string.
   if (size < ExternalString::kSize) {
     // The string is too small to fit an external String in its place. This can
@@ -773,7 +794,7 @@
 
   // Morph the object to an external string by adjusting the map and
   // reinitializing the fields.
-  this->set_map(Heap::external_ascii_string_map());
+  this->set_map(heap->external_ascii_string_map());
   ExternalAsciiString* self = ExternalAsciiString::cast(this);
   self->set_length(length);
   self->set_hash_field(hash_field);
@@ -783,12 +804,12 @@
   if (is_symbol) {
     self->Hash();  // Force regeneration of the hash value.
     // Now morph this external string into a external symbol.
-    this->set_map(Heap::external_ascii_symbol_map());
+    this->set_map(heap->external_ascii_symbol_map());
   }
 
   // Fill the remainder of the string with dead wood.
   int new_size = this->Size();  // Byte size of the external String object.
-  Heap::CreateFillerObjectAt(this->address() + new_size, size - new_size);
+  heap->CreateFillerObjectAt(this->address() + new_size, size - new_size);
   return true;
 }
 
@@ -887,15 +908,16 @@
     // All other JSObjects are rather similar to each other (JSObject,
     // JSGlobalProxy, JSGlobalObject, JSUndetectableObject, JSValue).
     default: {
+      Heap* heap = GetHeap();
       Object* constructor = map()->constructor();
       bool printed = false;
       if (constructor->IsHeapObject() &&
-          !Heap::Contains(HeapObject::cast(constructor))) {
+          !heap->Contains(HeapObject::cast(constructor))) {
         accumulator->Add("!!!INVALID CONSTRUCTOR!!!");
       } else {
         bool global_object = IsJSGlobalProxy();
         if (constructor->IsJSFunction()) {
-          if (!Heap::Contains(JSFunction::cast(constructor)->shared())) {
+          if (!heap->Contains(JSFunction::cast(constructor)->shared())) {
             accumulator->Add("!!!INVALID SHARED ON CONSTRUCTOR!!!");
           } else {
             Object* constructor_name =
@@ -930,12 +952,13 @@
 
 
 void HeapObject::HeapObjectShortPrint(StringStream* accumulator) {
-  // if (!Heap::InNewSpace(this)) PrintF("*", this);
-  if (!Heap::Contains(this)) {
+  // if (!HEAP->InNewSpace(this)) PrintF("*", this);
+  Heap* heap = GetHeap();
+  if (!heap->Contains(this)) {
     accumulator->Add("!!!INVALID POINTER!!!");
     return;
   }
-  if (!Heap::Contains(map())) {
+  if (!heap->Contains(map())) {
     accumulator->Add("!!!INVALID MAP!!!");
     return;
   }
@@ -1150,14 +1173,14 @@
   if (u.bits.exp == 2047) {
     // Detect NaN for IEEE double precision floating point.
     if ((u.bits.man_low | u.bits.man_high) != 0)
-      return Heap::false_value();
+      return GetHeap()->false_value();
   }
   if (u.bits.exp == 0) {
     // Detect +0, and -0 for IEEE double precision floating point.
     if ((u.bits.man_low | u.bits.man_high) == 0)
-      return Heap::false_value();
+      return GetHeap()->false_value();
   }
-  return Heap::true_value();
+  return GetHeap()->true_value();
 }
 
 
@@ -1181,14 +1204,14 @@
 
 String* JSObject::class_name() {
   if (IsJSFunction()) {
-    return Heap::function_class_symbol();
+    return GetHeap()->function_class_symbol();
   }
   if (map()->constructor()->IsJSFunction()) {
     JSFunction* constructor = JSFunction::cast(map()->constructor());
     return String::cast(constructor->shared()->instance_class_name());
   }
   // If the constructor is not present, return "Object".
-  return Heap::Object_symbol();
+  return GetHeap()->Object_symbol();
 }
 
 
@@ -1203,7 +1226,7 @@
     if (proto->IsJSObject()) return JSObject::cast(proto)->constructor_name();
   }
   // If the constructor is not present, return "Object".
-  return Heap::Object_symbol();
+  return GetHeap()->Object_symbol();
 }
 
 
@@ -1233,9 +1256,10 @@
 
   // Normalize the object if the name is an actual string (not the
   // hidden symbols) and is not a real identifier.
+  Isolate* isolate = GetHeap()->isolate();
   StringInputBuffer buffer(name);
-  if (!ScannerConstants::IsIdentifier(&buffer)
-      && name != Heap::hidden_symbol()) {
+  if (!isolate->scanner_constants()->IsIdentifier(&buffer)
+      && name != HEAP->hidden_symbol()) {
     Object* obj;
     { MaybeObject* maybe_obj =
           NormalizeProperties(CLEAR_INOBJECT_PROPERTIES, 0);
@@ -1262,7 +1286,8 @@
   // global object_function's map and there is not a transition for name.
   bool allow_map_transition =
         !old_descriptors->Contains(name) &&
-        (Top::context()->global_context()->object_function()->map() != map());
+        (isolate->context()->global_context()->object_function()->
+            map() != map());
 
   ASSERT(index < map()->inobject_properties() ||
          (index - map()->inobject_properties()) < properties()->length() ||
@@ -1316,7 +1341,8 @@
     String* name,
     JSFunction* function,
     PropertyAttributes attributes) {
-  ASSERT(!Heap::InNewSpace(function));
+  Heap* heap = GetHeap();
+  ASSERT(!heap->InNewSpace(function));
 
   // Allocate new instance descriptors with (name, function) added
   ConstantFunctionDescriptor d(name, function, attributes);
@@ -1341,7 +1367,8 @@
 
   // If the old map is the global object map (from new Object()),
   // then transitions are not added to it, so we are done.
-  if (old_map == Top::context()->global_context()->object_function()->map()) {
+  if (old_map == heap->isolate()->context()->global_context()->
+      object_function()->map()) {
     return function;
   }
 
@@ -1376,6 +1403,7 @@
                                        Object* value,
                                        PropertyAttributes attributes) {
   ASSERT(!HasFastProperties());
+  Heap* heap = GetHeap();
   StringDictionary* dict = property_dictionary();
   Object* store_value = value;
   if (IsGlobalObject()) {
@@ -1393,7 +1421,7 @@
       return value;
     }
     { MaybeObject* maybe_store_value =
-          Heap::AllocateJSGlobalPropertyCell(value);
+          heap->AllocateJSGlobalPropertyCell(value);
       if (!maybe_store_value->ToObject(&store_value)) return maybe_store_value;
     }
     JSGlobalPropertyCell::cast(store_value)->set_value(value);
@@ -1412,16 +1440,17 @@
                                    Object* value,
                                    PropertyAttributes attributes) {
   ASSERT(!IsJSGlobalProxy());
+  Heap* heap = GetHeap();
   if (!map()->is_extensible()) {
     Handle<Object> args[1] = {Handle<String>(name)};
-    return Top::Throw(*Factory::NewTypeError("object_not_extensible",
-                                             HandleVector(args, 1)));
+    return heap->isolate()->Throw(
+        *FACTORY->NewTypeError("object_not_extensible", HandleVector(args, 1)));
   }
   if (HasFastProperties()) {
     // Ensure the descriptor array does not get too big.
     if (map()->instance_descriptors()->number_of_descriptors() <
         DescriptorArray::kMaxNumberOfDescriptors) {
-      if (value->IsJSFunction() && !Heap::InNewSpace(value)) {
+      if (value->IsJSFunction() && !heap->InNewSpace(value)) {
         return AddConstantFunctionProperty(name,
                                            JSFunction::cast(value),
                                            attributes);
@@ -1493,7 +1522,8 @@
     return result;
   }
   // Do not add transitions to the map of "new Object()".
-  if (map() == Top::context()->global_context()->object_function()->map()) {
+  if (map() == GetHeap()->isolate()->context()->global_context()->
+      object_function()->map()) {
     return result;
   }
 
@@ -1580,29 +1610,31 @@
     Object* value,
     PropertyAttributes attributes,
     StrictModeFlag strict_mode) {
-  HandleScope scope;
+  Isolate* isolate = GetIsolate();
+  HandleScope scope(isolate);
   Handle<JSObject> this_handle(this);
   Handle<String> name_handle(name);
-  Handle<Object> value_handle(value);
+  Handle<Object> value_handle(value, isolate);
   Handle<InterceptorInfo> interceptor(GetNamedInterceptor());
   if (!interceptor->setter()->IsUndefined()) {
-    LOG(ApiNamedPropertyAccess("interceptor-named-set", this, name));
-    CustomArguments args(interceptor->data(), this, this);
+    LOG(isolate, ApiNamedPropertyAccess("interceptor-named-set", this, name));
+    CustomArguments args(isolate, interceptor->data(), this, this);
     v8::AccessorInfo info(args.end());
     v8::NamedPropertySetter setter =
         v8::ToCData<v8::NamedPropertySetter>(interceptor->setter());
     v8::Handle<v8::Value> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       Handle<Object> value_unhole(value->IsTheHole() ?
-                                  Heap::undefined_value() :
-                                  value);
+                                  isolate->heap()->undefined_value() :
+                                  value,
+                                  isolate);
       result = setter(v8::Utils::ToLocal(name_handle),
                       v8::Utils::ToLocal(value_unhole),
                       info);
     }
-    RETURN_IF_SCHEDULED_EXCEPTION();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
     if (!result.IsEmpty()) return *value_handle;
   }
   MaybeObject* raw_result =
@@ -1610,7 +1642,7 @@
                                               *value_handle,
                                               attributes,
                                               strict_mode);
-  RETURN_IF_SCHEDULED_EXCEPTION();
+  RETURN_IF_SCHEDULED_EXCEPTION(isolate);
   return raw_result;
 }
 
@@ -1629,12 +1661,13 @@
                                                String* name,
                                                Object* value,
                                                JSObject* holder) {
-  HandleScope scope;
+  Isolate* isolate = GetIsolate();
+  HandleScope scope(isolate);
 
   // We should never get here to initialize a const with the hole
   // value since a const declaration would conflict with the setter.
   ASSERT(!value->IsTheHole());
-  Handle<Object> value_handle(value);
+  Handle<Object> value_handle(value, isolate);
 
   // To accommodate both the old and the new api we switch on the
   // data structure used to store the callbacks.  Eventually proxy
@@ -1643,7 +1676,7 @@
     AccessorDescriptor* callback =
         reinterpret_cast<AccessorDescriptor*>(Proxy::cast(structure)->proxy());
     MaybeObject* obj = (callback->setter)(this,  value, callback->data);
-    RETURN_IF_SCHEDULED_EXCEPTION();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
     if (obj->IsFailure()) return obj;
     return *value_handle;
   }
@@ -1655,17 +1688,17 @@
     v8::AccessorSetter call_fun = v8::ToCData<v8::AccessorSetter>(call_obj);
     if (call_fun == NULL) return value;
     Handle<String> key(name);
-    LOG(ApiNamedPropertyAccess("store", this, name));
-    CustomArguments args(data->data(), this, JSObject::cast(holder));
+    LOG(isolate, ApiNamedPropertyAccess("store", this, name));
+    CustomArguments args(isolate, data->data(), this, JSObject::cast(holder));
     v8::AccessorInfo info(args.end());
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       call_fun(v8::Utils::ToLocal(key),
                v8::Utils::ToLocal(value_handle),
                info);
     }
-    RETURN_IF_SCHEDULED_EXCEPTION();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
     return *value_handle;
   }
 
@@ -1675,10 +1708,11 @@
      return SetPropertyWithDefinedSetter(JSFunction::cast(setter), value);
     } else {
       Handle<String> key(name);
-      Handle<Object> holder_handle(holder);
+      Handle<Object> holder_handle(holder, isolate);
       Handle<Object> args[2] = { key, holder_handle };
-      return Top::Throw(*Factory::NewTypeError("no_setter_in_callback",
-                                               HandleVector(args, 2)));
+      return isolate->Throw(
+          *isolate->factory()->NewTypeError("no_setter_in_callback",
+                                            HandleVector(args, 2)));
     }
   }
 
@@ -1689,13 +1723,15 @@
 
 MaybeObject* JSObject::SetPropertyWithDefinedSetter(JSFunction* setter,
                                                     Object* value) {
-  Handle<Object> value_handle(value);
-  Handle<JSFunction> fun(JSFunction::cast(setter));
-  Handle<JSObject> self(this);
+  Isolate* isolate = GetIsolate();
+  Handle<Object> value_handle(value, isolate);
+  Handle<JSFunction> fun(JSFunction::cast(setter), isolate);
+  Handle<JSObject> self(this, isolate);
 #ifdef ENABLE_DEBUGGER_SUPPORT
+  Debug* debug = isolate->debug();
   // Handle stepping into a setter if step into is active.
-  if (Debug::StepInActive()) {
-    Debug::HandleStepIn(fun, Handle<Object>::null(), 0, false);
+  if (debug->StepInActive()) {
+    debug->HandleStepIn(fun, Handle<Object>::null(), 0, false);
   }
 #endif
   bool has_pending_exception;
@@ -1709,8 +1745,9 @@
 
 void JSObject::LookupCallbackSetterInPrototypes(String* name,
                                                 LookupResult* result) {
+  Heap* heap = GetHeap();
   for (Object* pt = GetPrototype();
-       pt != Heap::null_value();
+       pt != heap->null_value();
        pt = pt->GetPrototype()) {
     JSObject::cast(pt)->LocalLookupRealNamedProperty(name, result);
     if (result->IsProperty()) {
@@ -1730,8 +1767,9 @@
 MaybeObject* JSObject::SetElementWithCallbackSetterInPrototypes(uint32_t index,
                                                                 Object* value,
                                                                 bool* found) {
+  Heap* heap = GetHeap();
   for (Object* pt = GetPrototype();
-       pt != Heap::null_value();
+       pt != heap->null_value();
        pt = pt->GetPrototype()) {
     if (!JSObject::cast(pt)->HasDictionaryElements()) {
         continue;
@@ -1748,7 +1786,7 @@
     }
   }
   *found = false;
-  return Heap::the_hole_value();
+  return heap->the_hole_value();
 }
 
 
@@ -1767,10 +1805,11 @@
                               String* name,
                               LookupResult* result) {
   DescriptorArray* descriptors = instance_descriptors();
-  int number = DescriptorLookupCache::Lookup(descriptors, name);
+  DescriptorLookupCache* cache = heap()->isolate()->descriptor_lookup_cache();
+  int number = cache->Lookup(descriptors, name);
   if (number == DescriptorLookupCache::kAbsent) {
     number = descriptors->Search(name);
-    DescriptorLookupCache::Update(descriptors, name, number);
+    cache->Update(descriptors, name, number);
   }
   if (number != DescriptorArray::kNotFound) {
     result->DescriptorResult(holder, descriptors->GetDetails(number), number);
@@ -1838,8 +1877,9 @@
 
 void JSObject::LookupRealNamedPropertyInPrototypes(String* name,
                                                    LookupResult* result) {
+  Heap* heap = GetHeap();
   for (Object* pt = GetPrototype();
-       pt != Heap::null_value();
+       pt != heap->null_value();
        pt = JSObject::cast(pt)->GetPrototype()) {
     JSObject::cast(pt)->LocalLookupRealNamedProperty(name, result);
     if (result->IsProperty() && (result->type() != INTERCEPTOR)) return;
@@ -1853,6 +1893,7 @@
                                                         String* name,
                                                         Object* value,
                                                         bool check_prototype) {
+  Heap* heap = GetHeap();
   if (check_prototype && !result->IsProperty()) {
     LookupCallbackSetterInPrototypes(name, result);
   }
@@ -1893,7 +1934,7 @@
 
   HandleScope scope;
   Handle<Object> value_handle(value);
-  Top::ReportFailedAccessCheck(this, v8::ACCESS_SET);
+  heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_SET);
   return *value_handle;
 }
 
@@ -1903,6 +1944,7 @@
                                    Object* value,
                                    PropertyAttributes attributes,
                                    StrictModeFlag strict_mode) {
+  Heap* heap = GetHeap();
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
   AssertNoContextChange ncc;
@@ -1912,7 +1954,7 @@
   // reallocating them.
   if (!name->IsSymbol() && name->length() <= 2) {
     Object* symbol_version;
-    { MaybeObject* maybe_symbol_version = Heap::LookupSymbol(name);
+    { MaybeObject* maybe_symbol_version = heap->LookupSymbol(name);
       if (maybe_symbol_version->ToObject(&symbol_version)) {
         name = String::cast(symbol_version);
       }
@@ -1921,7 +1963,7 @@
 
   // Check access rights if needed.
   if (IsAccessCheckNeeded()
-      && !Top::MayNamedAccess(this, name, v8::ACCESS_SET)) {
+      && !heap->isolate()->MayNamedAccess(this, name, v8::ACCESS_SET)) {
     return SetPropertyWithFailedAccessCheck(result, name, value, true);
   }
 
@@ -1955,8 +1997,8 @@
       Handle<String> key(name);
       Handle<Object> holder(this);
       Handle<Object> args[2] = { key, holder };
-      return Top::Throw(*Factory::NewTypeError("strict_read_only_property",
-                                                HandleVector(args, 2)));
+      return heap->isolate()->Throw(*heap->isolate()->factory()->NewTypeError(
+          "strict_read_only_property", HandleVector(args, 2)));
     } else {
       return value;
     }
@@ -1999,7 +2041,7 @@
       ASSERT(target_descriptors->GetType(number) == CONSTANT_FUNCTION);
       JSFunction* function =
           JSFunction::cast(target_descriptors->GetValue(number));
-      ASSERT(!Heap::InNewSpace(function));
+      ASSERT(!HEAP->InNewSpace(function));
       if (value == function) {
         set_map(target_map);
         return value;
@@ -2028,6 +2070,8 @@
     String* name,
     Object* value,
     PropertyAttributes attributes) {
+  Heap* heap = GetHeap();
+
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
   AssertNoContextChange ncc;
@@ -2035,7 +2079,7 @@
   LocalLookup(name, &result);
   // Check access rights if needed.
   if (IsAccessCheckNeeded()
-      && !Top::MayNamedAccess(this, name, v8::ACCESS_SET)) {
+      && !heap->isolate()->MayNamedAccess(this, name, v8::ACCESS_SET)) {
     return SetPropertyWithFailedAccessCheck(&result, name, value, false);
   }
 
@@ -2107,7 +2151,7 @@
   if (continue_search) {
     // Continue searching via the prototype chain.
     Object* pt = GetPrototype();
-    if (pt != Heap::null_value()) {
+    if (!pt->IsNull()) {
       return JSObject::cast(pt)->
         GetPropertyAttributeWithReceiver(receiver, name);
     }
@@ -2120,25 +2164,28 @@
       JSObject* receiver,
       String* name,
       bool continue_search) {
+  Isolate* isolate = GetIsolate();
+
   // Make sure that the top context does not change when doing
   // callbacks or interceptor calls.
   AssertNoContextChange ncc;
 
-  HandleScope scope;
+  HandleScope scope(isolate);
   Handle<InterceptorInfo> interceptor(GetNamedInterceptor());
   Handle<JSObject> receiver_handle(receiver);
   Handle<JSObject> holder_handle(this);
   Handle<String> name_handle(name);
-  CustomArguments args(interceptor->data(), receiver, this);
+  CustomArguments args(isolate, interceptor->data(), receiver, this);
   v8::AccessorInfo info(args.end());
   if (!interceptor->query()->IsUndefined()) {
     v8::NamedPropertyQuery query =
         v8::ToCData<v8::NamedPropertyQuery>(interceptor->query());
-    LOG(ApiNamedPropertyAccess("interceptor-named-has", *holder_handle, name));
+    LOG(isolate,
+        ApiNamedPropertyAccess("interceptor-named-has", *holder_handle, name));
     v8::Handle<v8::Integer> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       result = query(v8::Utils::ToLocal(name_handle), info);
     }
     if (!result.IsEmpty()) {
@@ -2148,11 +2195,12 @@
   } else if (!interceptor->getter()->IsUndefined()) {
     v8::NamedPropertyGetter getter =
         v8::ToCData<v8::NamedPropertyGetter>(interceptor->getter());
-    LOG(ApiNamedPropertyAccess("interceptor-named-get-has", this, name));
+    LOG(isolate,
+        ApiNamedPropertyAccess("interceptor-named-get-has", this, name));
     v8::Handle<v8::Value> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       result = getter(v8::Utils::ToLocal(name_handle), info);
     }
     if (!result.IsEmpty()) return DONT_ENUM;
@@ -2182,9 +2230,10 @@
                                                   LookupResult* result,
                                                   String* name,
                                                   bool continue_search) {
+  Heap* heap = GetHeap();
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayNamedAccess(this, name, v8::ACCESS_HAS)) {
+      !heap->isolate()->MayNamedAccess(this, name, v8::ACCESS_HAS)) {
     return GetPropertyAttributeWithFailedAccessCheck(receiver,
                                                      result,
                                                      name,
@@ -2250,7 +2299,7 @@
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
   set(index, result);
-  Counters::normalized_maps.Increment();
+  COUNTERS->normalized_maps()->Increment();
 
   return result;
 }
@@ -2310,7 +2359,7 @@
                                                      UNIQUE_NORMALIZED_MAP);
       if (!maybe_obj->ToObject(&obj)) return maybe_obj;
     }
-    Counters::normalized_maps.Increment();
+    COUNTERS->normalized_maps()->Increment();
 
     set_map(Map::cast(obj));
   }
@@ -2324,10 +2373,11 @@
 
   // The global object is always normalized.
   ASSERT(!IsGlobalObject());
-
   // JSGlobalProxy must never be normalized
   ASSERT(!IsJSGlobalProxy());
 
+  Heap* heap = GetHeap();
+
   // Allocate new content.
   int property_count = map()->NumberOfDescribedProperties();
   if (expected_additional_properties > 0) {
@@ -2396,8 +2446,8 @@
   int index = map()->instance_descriptors()->NextEnumerationIndex();
   dictionary->SetNextEnumerationIndex(index);
 
-  { MaybeObject* maybe_obj = Top::context()->global_context()->
-                normalized_map_cache()->Get(this, mode);
+  { MaybeObject* maybe_obj = heap->isolate()->context()->global_context()->
+        normalized_map_cache()->Get(this, mode);
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   Map* new_map = Map::cast(obj);
@@ -2409,14 +2459,15 @@
   int new_instance_size = new_map->instance_size();
   int instance_size_delta = map()->instance_size() - new_instance_size;
   ASSERT(instance_size_delta >= 0);
-  Heap::CreateFillerObjectAt(this->address() + new_instance_size,
+  heap->CreateFillerObjectAt(this->address() + new_instance_size,
                              instance_size_delta);
 
   set_map(new_map);
+  map()->set_instance_descriptors(heap->empty_descriptor_array());
 
   set_properties(dictionary);
 
-  Counters::props_to_dictionary.Increment();
+  heap->isolate()->counters()->props_to_dictionary()->Increment();
 
 #ifdef DEBUG
   if (FLAG_trace_normalization) {
@@ -2477,7 +2528,8 @@
   set_map(new_map);
   set_elements(dictionary);
 
-  Counters::elements_to_dictionary.Increment();
+  new_map->GetHeap()->isolate()->counters()->elements_to_dictionary()->
+      Increment();
 
 #ifdef DEBUG
   if (FLAG_trace_normalization) {
@@ -2493,9 +2545,10 @@
 MaybeObject* JSObject::DeletePropertyPostInterceptor(String* name,
                                                      DeleteMode mode) {
   // Check local property, ignore interceptor.
+  Heap* heap = GetHeap();
   LookupResult result;
   LocalLookupRealNamedProperty(name, &result);
-  if (!result.IsProperty()) return Heap::true_value();
+  if (!result.IsProperty()) return heap->true_value();
 
   // Normalize object if needed.
   Object* obj;
@@ -2508,23 +2561,25 @@
 
 
 MaybeObject* JSObject::DeletePropertyWithInterceptor(String* name) {
-  HandleScope scope;
+  Isolate* isolate = GetIsolate();
+  HandleScope scope(isolate);
   Handle<InterceptorInfo> interceptor(GetNamedInterceptor());
   Handle<String> name_handle(name);
   Handle<JSObject> this_handle(this);
   if (!interceptor->deleter()->IsUndefined()) {
     v8::NamedPropertyDeleter deleter =
         v8::ToCData<v8::NamedPropertyDeleter>(interceptor->deleter());
-    LOG(ApiNamedPropertyAccess("interceptor-named-delete", *this_handle, name));
-    CustomArguments args(interceptor->data(), this, this);
+    LOG(isolate,
+        ApiNamedPropertyAccess("interceptor-named-delete", *this_handle, name));
+    CustomArguments args(isolate, interceptor->data(), this, this);
     v8::AccessorInfo info(args.end());
     v8::Handle<v8::Boolean> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       result = deleter(v8::Utils::ToLocal(name_handle), info);
     }
-    RETURN_IF_SCHEDULED_EXCEPTION();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
     if (!result.IsEmpty()) {
       ASSERT(result->IsBoolean());
       return *v8::Utils::OpenHandle(*result);
@@ -2532,13 +2587,14 @@
   }
   MaybeObject* raw_result =
       this_handle->DeletePropertyPostInterceptor(*name_handle, NORMAL_DELETION);
-  RETURN_IF_SCHEDULED_EXCEPTION();
+  RETURN_IF_SCHEDULED_EXCEPTION(isolate);
   return raw_result;
 }
 
 
 MaybeObject* JSObject::DeleteElementPostInterceptor(uint32_t index,
                                                     DeleteMode mode) {
+  Heap* heap = GetHeap();
   ASSERT(!HasExternalArrayElements());
   switch (GetElementsKind()) {
     case FAST_ELEMENTS: {
@@ -2566,52 +2622,56 @@
       UNREACHABLE();
       break;
   }
-  return Heap::true_value();
+  return heap->true_value();
 }
 
 
 MaybeObject* JSObject::DeleteElementWithInterceptor(uint32_t index) {
+  Isolate* isolate = GetIsolate();
+  Heap* heap = isolate->heap();
   // Make sure that the top context does not change when doing
   // callbacks or interceptor calls.
   AssertNoContextChange ncc;
-  HandleScope scope;
+  HandleScope scope(isolate);
   Handle<InterceptorInfo> interceptor(GetIndexedInterceptor());
-  if (interceptor->deleter()->IsUndefined()) return Heap::false_value();
+  if (interceptor->deleter()->IsUndefined()) return heap->false_value();
   v8::IndexedPropertyDeleter deleter =
       v8::ToCData<v8::IndexedPropertyDeleter>(interceptor->deleter());
   Handle<JSObject> this_handle(this);
-  LOG(ApiIndexedPropertyAccess("interceptor-indexed-delete", this, index));
-  CustomArguments args(interceptor->data(), this, this);
+  LOG(isolate,
+      ApiIndexedPropertyAccess("interceptor-indexed-delete", this, index));
+  CustomArguments args(isolate, interceptor->data(), this, this);
   v8::AccessorInfo info(args.end());
   v8::Handle<v8::Boolean> result;
   {
     // Leaving JavaScript.
-    VMState state(EXTERNAL);
+    VMState state(isolate, EXTERNAL);
     result = deleter(index, info);
   }
-  RETURN_IF_SCHEDULED_EXCEPTION();
+  RETURN_IF_SCHEDULED_EXCEPTION(isolate);
   if (!result.IsEmpty()) {
     ASSERT(result->IsBoolean());
     return *v8::Utils::OpenHandle(*result);
   }
   MaybeObject* raw_result =
       this_handle->DeleteElementPostInterceptor(index, NORMAL_DELETION);
-  RETURN_IF_SCHEDULED_EXCEPTION();
+  RETURN_IF_SCHEDULED_EXCEPTION(isolate);
   return raw_result;
 }
 
 
 MaybeObject* JSObject::DeleteElement(uint32_t index, DeleteMode mode) {
+  Isolate* isolate = GetIsolate();
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayIndexedAccess(this, index, v8::ACCESS_DELETE)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_DELETE);
-    return Heap::false_value();
+      !isolate->MayIndexedAccess(this, index, v8::ACCESS_DELETE)) {
+    isolate->ReportFailedAccessCheck(this, v8::ACCESS_DELETE);
+    return isolate->heap()->false_value();
   }
 
   if (IsJSGlobalProxy()) {
     Object* proto = GetPrototype();
-    if (proto->IsNull()) return Heap::false_value();
+    if (proto->IsNull()) return isolate->heap()->false_value();
     ASSERT(proto->IsJSGlobalObject());
     return JSGlobalObject::cast(proto)->DeleteElement(index, mode);
   }
@@ -2654,15 +2714,16 @@
       int entry = dictionary->FindEntry(index);
       if (entry != NumberDictionary::kNotFound) {
         Object* result = dictionary->DeleteProperty(entry, mode);
-        if (mode == STRICT_DELETION && result == Heap::false_value()) {
+        if (mode == STRICT_DELETION && result ==
+            isolate->heap()->false_value()) {
           // In strict mode, deleting a non-configurable property throws
           // exception. dictionary->DeleteProperty will return false_value()
           // if a non-configurable property is being deleted.
           HandleScope scope;
-          Handle<Object> i = Factory::NewNumberFromUint(index);
+          Handle<Object> i = isolate->factory()->NewNumberFromUint(index);
           Handle<Object> args[2] = { i, Handle<Object>(this) };
-          return Top::Throw(*Factory::NewTypeError("strict_delete_property",
-                                                   HandleVector(args, 2)));
+          return isolate->Throw(*isolate->factory()->NewTypeError(
+              "strict_delete_property", HandleVector(args, 2)));
         }
       }
       break;
@@ -2671,24 +2732,25 @@
       UNREACHABLE();
       break;
   }
-  return Heap::true_value();
+  return isolate->heap()->true_value();
 }
 
 
 MaybeObject* JSObject::DeleteProperty(String* name, DeleteMode mode) {
+  Isolate* isolate = GetIsolate();
   // ECMA-262, 3rd, 8.6.2.5
   ASSERT(name->IsString());
 
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayNamedAccess(this, name, v8::ACCESS_DELETE)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_DELETE);
-    return Heap::false_value();
+      !isolate->MayNamedAccess(this, name, v8::ACCESS_DELETE)) {
+    isolate->ReportFailedAccessCheck(this, v8::ACCESS_DELETE);
+    return isolate->heap()->false_value();
   }
 
   if (IsJSGlobalProxy()) {
     Object* proto = GetPrototype();
-    if (proto->IsNull()) return Heap::false_value();
+    if (proto->IsNull()) return isolate->heap()->false_value();
     ASSERT(proto->IsJSGlobalObject());
     return JSGlobalObject::cast(proto)->DeleteProperty(name, mode);
   }
@@ -2699,17 +2761,17 @@
   } else {
     LookupResult result;
     LocalLookup(name, &result);
-    if (!result.IsProperty()) return Heap::true_value();
+    if (!result.IsProperty()) return isolate->heap()->true_value();
     // Ignore attributes if forcing a deletion.
     if (result.IsDontDelete() && mode != FORCE_DELETION) {
       if (mode == STRICT_DELETION) {
         // Deleting a non-configurable property in strict mode.
-        HandleScope scope;
+        HandleScope scope(isolate);
         Handle<Object> args[2] = { Handle<Object>(name), Handle<Object>(this) };
-        return Top::Throw(*Factory::NewTypeError("strict_delete_property",
-                                                 HandleVector(args, 2)));
+        return isolate->Throw(*isolate->factory()->NewTypeError(
+            "strict_delete_property", HandleVector(args, 2)));
       }
-      return Heap::false_value();
+      return isolate->heap()->false_value();
     }
     // Check for interceptor.
     if (result.type() == INTERCEPTOR) {
@@ -2733,6 +2795,7 @@
 
 // Check whether this object references another object.
 bool JSObject::ReferencesObject(Object* obj) {
+  Heap* heap = GetHeap();
   AssertNoAllocation no_alloc;
 
   // Is the object the constructor for this object?
@@ -2747,7 +2810,7 @@
 
   // Check if the object is among the named properties.
   Object* key = SlowReverseLookup(obj);
-  if (key != Heap::undefined_value()) {
+  if (!key->IsUndefined()) {
     return true;
   }
 
@@ -2778,7 +2841,7 @@
     }
     case DICTIONARY_ELEMENTS: {
       key = element_dictionary()->SlowReverseLookup(obj);
-      if (key != Heap::undefined_value()) {
+      if (!key->IsUndefined()) {
         return true;
       }
       break;
@@ -2792,7 +2855,8 @@
   if (IsJSFunction()) {
     // Get the constructor function for arguments array.
     JSObject* arguments_boilerplate =
-        Top::context()->global_context()->arguments_boilerplate();
+        heap->isolate()->context()->global_context()->
+            arguments_boilerplate();
     JSFunction* arguments_function =
         JSFunction::cast(arguments_boilerplate->map()->constructor());
 
@@ -2831,10 +2895,13 @@
 
 
 MaybeObject* JSObject::PreventExtensions() {
+  Isolate* isolate = GetIsolate();
   if (IsAccessCheckNeeded() &&
-      !Top::MayNamedAccess(this, Heap::undefined_value(), v8::ACCESS_KEYS)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_KEYS);
-    return Heap::false_value();
+      !isolate->MayNamedAccess(this,
+                               isolate->heap()->undefined_value(),
+                               v8::ACCESS_KEYS)) {
+    isolate->ReportFailedAccessCheck(this, v8::ACCESS_KEYS);
+    return isolate->heap()->false_value();
   }
 
   if (IsJSGlobalProxy()) {
@@ -2873,8 +2940,9 @@
 // - This object has no elements.
 // - No prototype has enumerable properties/elements.
 bool JSObject::IsSimpleEnum() {
+  Heap* heap = GetHeap();
   for (Object* o = this;
-       o != Heap::null_value();
+       o != heap->null_value();
        o = JSObject::cast(o)->GetPrototype()) {
     JSObject* curr = JSObject::cast(o);
     if (!curr->map()->instance_descriptors()->HasEnumCache()) return false;
@@ -2940,6 +3008,8 @@
 void JSObject::LocalLookup(String* name, LookupResult* result) {
   ASSERT(name->IsString());
 
+  Heap* heap = GetHeap();
+
   if (IsJSGlobalProxy()) {
     Object* proto = GetPrototype();
     if (proto->IsNull()) return result->NotFound();
@@ -2954,13 +3024,14 @@
   }
 
   // Check __proto__ before interceptor.
-  if (name->Equals(Heap::Proto_symbol()) && !IsJSContextExtensionObject()) {
+  if (name->Equals(heap->Proto_symbol()) &&
+      !IsJSContextExtensionObject()) {
     result->ConstantResult(this);
     return;
   }
 
   // Check for lookup interceptor except when bootstrapping.
-  if (HasNamedInterceptor() && !Bootstrapper::IsActive()) {
+  if (HasNamedInterceptor() && !heap->isolate()->bootstrapper()->IsActive()) {
     result->InterceptorResult(this);
     return;
   }
@@ -2971,8 +3042,9 @@
 
 void JSObject::Lookup(String* name, LookupResult* result) {
   // Ecma-262 3rd 8.6.2.4
+  Heap* heap = GetHeap();
   for (Object* current = this;
-       current != Heap::null_value();
+       current != heap->null_value();
        current = JSObject::cast(current)->GetPrototype()) {
     JSObject::cast(current)->LocalLookup(name, result);
     if (result->IsProperty()) return;
@@ -2983,8 +3055,9 @@
 
 // Search object and it's prototype chain for callback properties.
 void JSObject::LookupCallback(String* name, LookupResult* result) {
+  Heap* heap = GetHeap();
   for (Object* current = this;
-       current != Heap::null_value();
+       current != heap->null_value();
        current = JSObject::cast(current)->GetPrototype()) {
     JSObject::cast(current)->LocalLookupRealNamedProperty(name, result);
     if (result->IsProperty() && result->type() == CALLBACKS) return;
@@ -2995,6 +3068,7 @@
 
 MaybeObject* JSObject::DefineGetterSetter(String* name,
                                           PropertyAttributes attributes) {
+  Heap* heap = GetHeap();
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
   AssertNoContextChange ncc;
@@ -3003,7 +3077,7 @@
   name->TryFlatten();
 
   if (!CanSetCallback(name)) {
-    return Heap::undefined_value();
+    return heap->undefined_value();
   }
 
   uint32_t index = 0;
@@ -3023,7 +3097,7 @@
       case EXTERNAL_FLOAT_ELEMENTS:
         // Ignore getters and setters on pixel and external array
         // elements.
-        return Heap::undefined_value();
+        return heap->undefined_value();
       case DICTIONARY_ELEMENTS: {
         // Lookup the index.
         NumberDictionary* dictionary = element_dictionary();
@@ -3031,7 +3105,7 @@
         if (entry != NumberDictionary::kNotFound) {
           Object* result = dictionary->ValueAt(entry);
           PropertyDetails details = dictionary->DetailsAt(entry);
-          if (details.IsReadOnly()) return Heap::undefined_value();
+          if (details.IsReadOnly()) return heap->undefined_value();
           if (details.type() == CALLBACKS) {
             if (result->IsFixedArray()) {
               return result;
@@ -3050,7 +3124,7 @@
     LookupResult result;
     LocalLookup(name, &result);
     if (result.IsProperty()) {
-      if (result.IsReadOnly()) return Heap::undefined_value();
+      if (result.IsReadOnly()) return heap->undefined_value();
       if (result.type() == CALLBACKS) {
         Object* obj = result.GetCallbackObject();
         // Need to preserve old getters/setters.
@@ -3064,7 +3138,7 @@
 
   // Allocate the fixed array to hold getter and setter.
   Object* structure;
-  { MaybeObject* maybe_structure = Heap::AllocateFixedArray(2, TENURED);
+  { MaybeObject* maybe_structure = heap->AllocateFixedArray(2, TENURED);
     if (!maybe_structure->ToObject(&structure)) return maybe_structure;
   }
 
@@ -3078,7 +3152,7 @@
 
 bool JSObject::CanSetCallback(String* name) {
   ASSERT(!IsAccessCheckNeeded()
-         || Top::MayNamedAccess(this, name, v8::ACCESS_SET));
+         || Isolate::Current()->MayNamedAccess(this, name, v8::ACCESS_SET));
 
   // Check if there is an API defined callback object which prohibits
   // callback overwriting in this object or it's prototype chain.
@@ -3175,11 +3249,12 @@
                                       Object* fun,
                                       PropertyAttributes attributes) {
   ASSERT(fun->IsJSFunction() || fun->IsUndefined());
+  Isolate* isolate = GetIsolate();
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayNamedAccess(this, name, v8::ACCESS_SET)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_SET);
-    return Heap::undefined_value();
+      !isolate->MayNamedAccess(this, name, v8::ACCESS_SET)) {
+    isolate->ReportFailedAccessCheck(this, v8::ACCESS_SET);
+    return isolate->heap()->undefined_value();
   }
 
   if (IsJSGlobalProxy()) {
@@ -3201,12 +3276,13 @@
 
 
 MaybeObject* JSObject::DefineAccessor(AccessorInfo* info) {
+  Isolate* isolate = GetIsolate();
   String* name = String::cast(info->name());
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayNamedAccess(this, name, v8::ACCESS_SET)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_SET);
-    return Heap::undefined_value();
+      !isolate->MayNamedAccess(this, name, v8::ACCESS_SET)) {
+    isolate->ReportFailedAccessCheck(this, v8::ACCESS_SET);
+    return isolate->heap()->undefined_value();
   }
 
   if (IsJSGlobalProxy()) {
@@ -3224,14 +3300,14 @@
   name->TryFlatten();
 
   if (!CanSetCallback(name)) {
-    return Heap::undefined_value();
+    return isolate->heap()->undefined_value();
   }
 
   uint32_t index = 0;
   bool is_element = name->AsArrayIndex(&index);
 
   if (is_element) {
-    if (IsJSArray()) return Heap::undefined_value();
+    if (IsJSArray()) return isolate->heap()->undefined_value();
 
     // Accessors overwrite previous callbacks (cf. with getters/setters).
     switch (GetElementsKind()) {
@@ -3247,7 +3323,7 @@
       case EXTERNAL_FLOAT_ELEMENTS:
         // Ignore getters and setters on pixel and external array
         // elements.
-        return Heap::undefined_value();
+        return isolate->heap()->undefined_value();
       case DICTIONARY_ELEMENTS:
         break;
       default:
@@ -3267,7 +3343,7 @@
     // ES5 forbids turning a property into an accessor if it's not
     // configurable (that is IsDontDelete in ES3 and v8), see 8.6.1 (Table 5).
     if (result.IsProperty() && (result.IsReadOnly() || result.IsDontDelete())) {
-      return Heap::undefined_value();
+      return isolate->heap()->undefined_value();
     }
     Object* ok;
     { MaybeObject* maybe_ok =
@@ -3281,15 +3357,17 @@
 
 
 Object* JSObject::LookupAccessor(String* name, bool is_getter) {
+  Heap* heap = GetHeap();
+
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
   AssertNoContextChange ncc;
 
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayNamedAccess(this, name, v8::ACCESS_HAS)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_HAS);
-    return Heap::undefined_value();
+      !heap->isolate()->MayNamedAccess(this, name, v8::ACCESS_HAS)) {
+    heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_HAS);
+    return heap->undefined_value();
   }
 
   // Make the lookup and include prototypes.
@@ -3297,7 +3375,7 @@
   uint32_t index = 0;
   if (name->AsArrayIndex(&index)) {
     for (Object* obj = this;
-         obj != Heap::null_value();
+         obj != heap->null_value();
          obj = JSObject::cast(obj)->GetPrototype()) {
       JSObject* js_object = JSObject::cast(obj);
       if (js_object->HasDictionaryElements()) {
@@ -3316,12 +3394,12 @@
     }
   } else {
     for (Object* obj = this;
-         obj != Heap::null_value();
+         obj != heap->null_value();
          obj = JSObject::cast(obj)->GetPrototype()) {
       LookupResult result;
       JSObject::cast(obj)->LocalLookup(name, &result);
       if (result.IsProperty()) {
-        if (result.IsReadOnly()) return Heap::undefined_value();
+        if (result.IsReadOnly()) return heap->undefined_value();
         if (result.type() == CALLBACKS) {
           Object* obj = result.GetCallbackObject();
           if (obj->IsFixedArray()) {
@@ -3331,11 +3409,12 @@
       }
     }
   }
-  return Heap::undefined_value();
+  return heap->undefined_value();
 }
 
 
 Object* JSObject::SlowReverseLookup(Object* value) {
+  Heap* heap = GetHeap();
   if (HasFastProperties()) {
     DescriptorArray* descs = map()->instance_descriptors();
     for (int i = 0; i < descs->number_of_descriptors(); i++) {
@@ -3349,7 +3428,7 @@
         }
       }
     }
-    return Heap::undefined_value();
+    return heap->undefined_value();
   } else {
     return property_dictionary()->SlowReverseLookup(value);
   }
@@ -3357,9 +3436,10 @@
 
 
 MaybeObject* Map::CopyDropDescriptors() {
+  Heap* heap = GetHeap();
   Object* result;
   { MaybeObject* maybe_result =
-        Heap::AllocateMap(instance_type(), instance_size());
+        heap->AllocateMap(instance_type(), instance_size());
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
   Map::cast(result)->set_prototype(prototype());
@@ -3369,7 +3449,8 @@
   // pointing to the same transition which is bad because the garbage
   // collector relies on being able to reverse pointers from transitions
   // to maps.  If properties need to be retained use CopyDropTransitions.
-  Map::cast(result)->set_instance_descriptors(Heap::empty_descriptor_array());
+  Map::cast(result)->set_instance_descriptors(
+      heap->empty_descriptor_array());
   // Please note instance_type and instance_size are set when allocated.
   Map::cast(result)->set_inobject_properties(inobject_properties());
   Map::cast(result)->set_unused_property_fields(unused_property_fields());
@@ -3392,7 +3473,7 @@
   Map::cast(result)->set_bit_field(bit_field());
   Map::cast(result)->set_bit_field2(bit_field2());
   Map::cast(result)->set_is_shared(false);
-  Map::cast(result)->ClearCodeCache();
+  Map::cast(result)->ClearCodeCache(heap);
   return result;
 }
 
@@ -3406,7 +3487,7 @@
 
   Object* result;
   { MaybeObject* maybe_result =
-        Heap::AllocateMap(instance_type(), new_instance_size);
+        GetHeap()->AllocateMap(instance_type(), new_instance_size);
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
 
@@ -3451,7 +3532,7 @@
   // Allocate the code cache if not present.
   if (code_cache()->IsFixedArray()) {
     Object* result;
-    { MaybeObject* maybe_result = Heap::AllocateCodeCache();
+    { MaybeObject* maybe_result = GetHeap()->AllocateCodeCache();
       if (!maybe_result->ToObject(&result)) return maybe_result;
     }
     set_code_cache(result);
@@ -3467,7 +3548,7 @@
   if (!code_cache()->IsFixedArray()) {
     return CodeCache::cast(code_cache())->Lookup(name, flags);
   } else {
-    return Heap::undefined_value();
+    return GetHeap()->undefined_value();
   }
 }
 
@@ -3491,12 +3572,13 @@
 
 void Map::TraverseTransitionTree(TraverseCallback callback, void* data) {
   Map* current = this;
-  while (current != Heap::meta_map()) {
+  Map* meta_map = heap()->meta_map();
+  while (current != meta_map) {
     DescriptorArray* d = reinterpret_cast<DescriptorArray*>(
         *RawField(current, Map::kInstanceDescriptorsOffset));
-    if (d == Heap::empty_descriptor_array()) {
+    if (d == heap()->empty_descriptor_array()) {
       Map* prev = current->map();
-      current->set_map(Heap::meta_map());
+      current->set_map(meta_map);
       callback(current, data);
       current = prev;
       continue;
@@ -3521,9 +3603,9 @@
       }
     }
     if (!map_done) continue;
-    *map_or_index_field = Heap::fixed_array_map();
+    *map_or_index_field = heap()->fixed_array_map();
     Map* prev = current->map();
-    current->set_map(Heap::meta_map());
+    current->set_map(meta_map);
     callback(current, data);
     current = prev;
   }
@@ -3636,6 +3718,7 @@
 
 
 Object* CodeCache::LookupDefaultCache(String* name, Code::Flags flags) {
+  Heap* heap = GetHeap();
   FixedArray* cache = default_cache();
   int length = cache->length();
   for (int i = 0; i < length; i += kCodeCacheEntrySize) {
@@ -3650,7 +3733,7 @@
       }
     }
   }
-  return Heap::undefined_value();
+  return heap->undefined_value();
 }
 
 
@@ -3659,7 +3742,7 @@
     CodeCacheHashTable* cache = CodeCacheHashTable::cast(normal_type_cache());
     return cache->Lookup(name, flags);
   } else {
-    return Heap::undefined_value();
+    return GetHeap()->undefined_value();
   }
 }
 
@@ -3741,7 +3824,7 @@
   MUST_USE_RESULT MaybeObject* AsObject() {
     ASSERT(code_ != NULL);
     Object* obj;
-    { MaybeObject* maybe_obj = Heap::AllocateFixedArray(2);
+    { MaybeObject* maybe_obj = code_->GetHeap()->AllocateFixedArray(2);
       if (!maybe_obj->ToObject(&obj)) return maybe_obj;
     }
     FixedArray* pair = FixedArray::cast(obj);
@@ -3760,7 +3843,7 @@
 Object* CodeCacheHashTable::Lookup(String* name, Code::Flags flags) {
   CodeCacheHashTableKey key(name, flags);
   int entry = FindEntry(&key);
-  if (entry == kNotFound) return Heap::undefined_value();
+  if (entry == kNotFound) return GetHeap()->undefined_value();
   return get(EntryToIndex(entry) + 1);
 }
 
@@ -3797,8 +3880,9 @@
 
 void CodeCacheHashTable::RemoveByIndex(int index) {
   ASSERT(index >= 0);
-  set(EntryToIndex(index), Heap::null_value());
-  set(EntryToIndex(index) + 1, Heap::null_value());
+  Heap* heap = GetHeap();
+  set(EntryToIndex(index), heap->null_value());
+  set(EntryToIndex(index) + 1, heap->null_value());
   ElementRemoved();
 }
 
@@ -3818,6 +3902,7 @@
 
 
 MaybeObject* FixedArray::AddKeysFromJSArray(JSArray* array) {
+  Heap* heap = GetHeap();
   ASSERT(!array->HasExternalArrayElements());
   switch (array->GetElementsKind()) {
     case JSObject::FAST_ELEMENTS:
@@ -3828,7 +3913,7 @@
 
       // Allocate a temporary fixed array.
       Object* object;
-      { MaybeObject* maybe_object = Heap::AllocateFixedArray(size);
+      { MaybeObject* maybe_object = heap->AllocateFixedArray(size);
         if (!maybe_object->ToObject(&object)) return maybe_object;
       }
       FixedArray* key_array = FixedArray::cast(object);
@@ -3848,11 +3933,12 @@
       UNREACHABLE();
   }
   UNREACHABLE();
-  return Heap::null_value();  // Failure case needs to "return" a value.
+  return heap->null_value();  // Failure case needs to "return" a value.
 }
 
 
 MaybeObject* FixedArray::UnionOfKeys(FixedArray* other) {
+  Heap* heap = GetHeap();
   int len0 = length();
 #ifdef DEBUG
   if (FLAG_enable_slow_asserts) {
@@ -3878,7 +3964,7 @@
 
   // Allocate the result
   Object* obj;
-  { MaybeObject* maybe_obj = Heap::AllocateFixedArray(len0 + extra);
+  { MaybeObject* maybe_obj = heap->AllocateFixedArray(len0 + extra);
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   // Fill in the content
@@ -3907,9 +3993,10 @@
 
 
 MaybeObject* FixedArray::CopySize(int new_length) {
-  if (new_length == 0) return Heap::empty_fixed_array();
+  Heap* heap = GetHeap();
+  if (new_length == 0) return heap->empty_fixed_array();
   Object* obj;
-  { MaybeObject* maybe_obj = Heap::AllocateFixedArray(new_length);
+  { MaybeObject* maybe_obj = heap->AllocateFixedArray(new_length);
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   FixedArray* result = FixedArray::cast(obj);
@@ -3947,13 +4034,14 @@
 
 
 MaybeObject* DescriptorArray::Allocate(int number_of_descriptors) {
+  Heap* heap = Isolate::Current()->heap();
   if (number_of_descriptors == 0) {
-    return Heap::empty_descriptor_array();
+    return heap->empty_descriptor_array();
   }
   // Allocate the array of keys.
   Object* array;
   { MaybeObject* maybe_array =
-        Heap::AllocateFixedArray(ToKeyIndex(number_of_descriptors));
+        heap->AllocateFixedArray(ToKeyIndex(number_of_descriptors));
     if (!maybe_array->ToObject(&array)) return maybe_array;
   }
   // Do not use DescriptorArray::cast on incomplete object.
@@ -3961,7 +4049,7 @@
 
   // Allocate the content array and set it in the descriptor array.
   { MaybeObject* maybe_array =
-        Heap::AllocateFixedArray(number_of_descriptors << 1);
+        heap->AllocateFixedArray(number_of_descriptors << 1);
     if (!maybe_array->ToObject(&array)) return maybe_array;
   }
   result->set(kContentArrayIndex, array);
@@ -4230,15 +4318,15 @@
 MaybeObject* DeoptimizationInputData::Allocate(int deopt_entry_count,
                                                PretenureFlag pretenure) {
   ASSERT(deopt_entry_count > 0);
-  return Heap::AllocateFixedArray(LengthFor(deopt_entry_count),
+  return HEAP->AllocateFixedArray(LengthFor(deopt_entry_count),
                                   pretenure);
 }
 
 
 MaybeObject* DeoptimizationOutputData::Allocate(int number_of_deopt_points,
                                                 PretenureFlag pretenure) {
-  if (number_of_deopt_points == 0) return Heap::empty_fixed_array();
-  return Heap::AllocateFixedArray(LengthOfFixedArray(number_of_deopt_points),
+  if (number_of_deopt_points == 0) return HEAP->empty_fixed_array();
+  return HEAP->AllocateFixedArray(LengthOfFixedArray(number_of_deopt_points),
                                   pretenure);
 }
 
@@ -4256,11 +4344,8 @@
 #endif
 
 
-static StaticResource<StringInputBuffer> string_input_buffer;
-
-
 bool String::LooksValid() {
-  if (!Heap::Contains(this)) return false;
+  if (!Isolate::Current()->heap()->Contains(this)) return false;
   return true;
 }
 
@@ -4271,8 +4356,10 @@
   // doesn't make Utf8Length faster, but it is very likely that
   // the string will be accessed later (for example by WriteUtf8)
   // so it's still a good idea.
+  Heap* heap = GetHeap();
   TryFlatten();
-  Access<StringInputBuffer> buffer(&string_input_buffer);
+  Access<StringInputBuffer> buffer(
+      heap->isolate()->objects_string_input_buffer());
   buffer->Reset(0, this);
   int result = 0;
   while (buffer->has_more())
@@ -4342,12 +4429,14 @@
   if (robust_flag == ROBUST_STRING_TRAVERSAL && !LooksValid()) {
     return SmartPointer<char>(NULL);
   }
+  Heap* heap = GetHeap();
 
   // Negative length means the to the end of the string.
   if (length < 0) length = kMaxInt - offset;
 
   // Compute the size of the UTF-8 string. Start at the specified offset.
-  Access<StringInputBuffer> buffer(&string_input_buffer);
+  Access<StringInputBuffer> buffer(
+      heap->isolate()->objects_string_input_buffer());
   buffer->Reset(offset, this);
   int character_position = offset;
   int utf8_bytes = 0;
@@ -4417,12 +4506,13 @@
 
 SmartPointer<uc16> String::ToWideCString(RobustnessFlag robust_flag) {
   ASSERT(NativeAllocationChecker::allocation_allowed());
-
   if (robust_flag == ROBUST_STRING_TRAVERSAL && !LooksValid()) {
     return SmartPointer<uc16>();
   }
+  Heap* heap = GetHeap();
 
-  Access<StringInputBuffer> buffer(&string_input_buffer);
+  Access<StringInputBuffer> buffer(
+      heap->isolate()->objects_string_input_buffer());
   buffer->Reset(this);
 
   uc16* result = NewArray<uc16>(length() + 1);
@@ -4705,11 +4795,9 @@
 }
 
 
-Relocatable* Relocatable::top_ = NULL;
-
-
 void Relocatable::PostGarbageCollectionProcessing() {
-  Relocatable* current = top_;
+  Isolate* isolate = Isolate::Current();
+  Relocatable* current = isolate->relocatable_top();
   while (current != NULL) {
     current->PostGarbageCollection();
     current = current->prev_;
@@ -4719,21 +4807,23 @@
 
 // Reserve space for statics needing saving and restoring.
 int Relocatable::ArchiveSpacePerThread() {
-  return sizeof(top_);
+  return sizeof(Isolate::Current()->relocatable_top());
 }
 
 
 // Archive statics that are thread local.
 char* Relocatable::ArchiveState(char* to) {
-  *reinterpret_cast<Relocatable**>(to) = top_;
-  top_ = NULL;
+  Isolate* isolate = Isolate::Current();
+  *reinterpret_cast<Relocatable**>(to) = isolate->relocatable_top();
+  isolate->set_relocatable_top(NULL);
   return to + ArchiveSpacePerThread();
 }
 
 
 // Restore statics that are thread local.
 char* Relocatable::RestoreState(char* from) {
-  top_ = *reinterpret_cast<Relocatable**>(from);
+  Isolate* isolate = Isolate::Current();
+  isolate->set_relocatable_top(*reinterpret_cast<Relocatable**>(from));
   return from + ArchiveSpacePerThread();
 }
 
@@ -4746,7 +4836,8 @@
 
 
 void Relocatable::Iterate(ObjectVisitor* v) {
-  Iterate(v, top_);
+  Isolate* isolate = Isolate::Current();
+  Iterate(v, isolate->relocatable_top());
 }
 
 
@@ -4759,15 +4850,17 @@
 }
 
 
-FlatStringReader::FlatStringReader(Handle<String> str)
-    : str_(str.location()),
+FlatStringReader::FlatStringReader(Isolate* isolate, Handle<String> str)
+    : Relocatable(isolate),
+      str_(str.location()),
       length_(str->length()) {
   PostGarbageCollection();
 }
 
 
-FlatStringReader::FlatStringReader(Vector<const char> input)
-    : str_(0),
+FlatStringReader::FlatStringReader(Isolate* isolate, Vector<const char> input)
+    : Relocatable(isolate),
+      str_(0),
       is_ascii_(true),
       length_(input.length()),
       start_(input.start()) { }
@@ -5097,11 +5190,10 @@
 }
 
 
-static StringInputBuffer string_compare_buffer_b;
-
-
 template <typename IteratorA>
-static inline bool CompareStringContentsPartial(IteratorA* ia, String* b) {
+static inline bool CompareStringContentsPartial(Isolate* isolate,
+                                                IteratorA* ia,
+                                                String* b) {
   if (b->IsFlat()) {
     if (b->IsAsciiRepresentation()) {
       VectorIterator<char> ib(b->ToAsciiVector());
@@ -5111,16 +5203,16 @@
       return CompareStringContents(ia, &ib);
     }
   } else {
-    string_compare_buffer_b.Reset(0, b);
-    return CompareStringContents(ia, &string_compare_buffer_b);
+    isolate->objects_string_compare_buffer_b()->Reset(0, b);
+    return CompareStringContents(ia,
+                                 isolate->objects_string_compare_buffer_b());
   }
 }
 
 
-static StringInputBuffer string_compare_buffer_a;
+bool String::SlowEquals(String* other) {
+  Heap* heap = GetHeap();
 
-
-bool String::SlowEquals(String* other) {
   // Fast check: negative check with lengths.
   int len = length();
   if (len != other->length()) return false;
@@ -5147,6 +5239,7 @@
                                     Vector<const char>(str2, len));
   }
 
+  Isolate* isolate = heap->isolate();
   if (lhs->IsFlat()) {
     if (lhs->IsAsciiRepresentation()) {
       Vector<const char> vec1 = lhs->ToAsciiVector();
@@ -5161,8 +5254,9 @@
         }
       } else {
         VectorIterator<char> buf1(vec1);
-        string_compare_buffer_b.Reset(0, rhs);
-        return CompareStringContents(&buf1, &string_compare_buffer_b);
+        isolate->objects_string_compare_buffer_b()->Reset(0, rhs);
+        return CompareStringContents(&buf1,
+            isolate->objects_string_compare_buffer_b());
       }
     } else {
       Vector<const uc16> vec1 = lhs->ToUC16Vector();
@@ -5177,13 +5271,15 @@
         }
       } else {
         VectorIterator<uc16> buf1(vec1);
-        string_compare_buffer_b.Reset(0, rhs);
-        return CompareStringContents(&buf1, &string_compare_buffer_b);
+        isolate->objects_string_compare_buffer_b()->Reset(0, rhs);
+        return CompareStringContents(&buf1,
+            isolate->objects_string_compare_buffer_b());
       }
     }
   } else {
-    string_compare_buffer_a.Reset(0, lhs);
-    return CompareStringContentsPartial(&string_compare_buffer_a, rhs);
+    isolate->objects_string_compare_buffer_a()->Reset(0, lhs);
+    return CompareStringContentsPartial(isolate,
+        isolate->objects_string_compare_buffer_a(), rhs);
   }
 }
 
@@ -5192,11 +5288,12 @@
   if (StringShape(this).IsSymbol()) return false;
 
   Map* map = this->map();
-  if (map == Heap::string_map()) {
-    this->set_map(Heap::undetectable_string_map());
+  Heap* heap = map->GetHeap();
+  if (map == heap->string_map()) {
+    this->set_map(heap->undetectable_string_map());
     return true;
-  } else if (map == Heap::ascii_string_map()) {
-    this->set_map(Heap::undetectable_ascii_string_map());
+  } else if (map == heap->ascii_string_map()) {
+    this->set_map(heap->undetectable_ascii_string_map());
     return true;
   }
   // Rest cannot be marked as undetectable
@@ -5205,9 +5302,10 @@
 
 
 bool String::IsEqualTo(Vector<const char> str) {
+  Isolate* isolate = GetIsolate();
   int slen = length();
   Access<ScannerConstants::Utf8Decoder>
-      decoder(ScannerConstants::utf8_decoder());
+      decoder(isolate->scanner_constants()->utf8_decoder());
   decoder->Reset(str.start(), str.length());
   int i;
   for (i = 0; i < slen && decoder->has_more(); i++) {
@@ -5369,8 +5467,9 @@
 
 
 MaybeObject* String::SubString(int start, int end, PretenureFlag pretenure) {
+  Heap* heap = GetHeap();
   if (start == 0 && end == length()) return this;
-  MaybeObject* result = Heap::AllocateSubString(this, start, end, pretenure);
+  MaybeObject* result = heap->AllocateSubString(this, start, end, pretenure);
   return result;
 }
 
@@ -5410,12 +5509,12 @@
 }
 
 
-void Map::ClearNonLiveTransitions(Object* real_prototype) {
+void Map::ClearNonLiveTransitions(Heap* heap, Object* real_prototype) {
   // Live DescriptorArray objects will be marked, so we must use
   // low-level accessors to get and modify their data.
   DescriptorArray* d = reinterpret_cast<DescriptorArray*>(
       *RawField(this, Map::kInstanceDescriptorsOffset));
-  if (d == Heap::raw_unchecked_empty_descriptor_array()) return;
+  if (d == heap->raw_unchecked_empty_descriptor_array()) return;
   Smi* NullDescriptorDetails =
     PropertyDetails(NONE, NULL_DESCRIPTOR).AsSmi();
   FixedArray* contents = reinterpret_cast<FixedArray*>(
@@ -5435,7 +5534,7 @@
       if (!target->IsMarked()) {
         ASSERT(target->IsMap());
         contents->set_unchecked(i + 1, NullDescriptorDetails);
-        contents->set_null_unchecked(i);
+        contents->set_null_unchecked(heap, i);
         ASSERT(target->prototype() == this ||
                target->prototype() == real_prototype);
         // Getter prototype() is read-only, set_prototype() has side effects.
@@ -5459,7 +5558,8 @@
   ASSERT(is_compiled() && !IsOptimized());
   ASSERT(shared()->allows_lazy_compilation() ||
          code()->optimizable());
-  ReplaceCode(Builtins::builtin(Builtins::LazyRecompile));
+  Builtins* builtins = GetIsolate()->builtins();
+  ReplaceCode(builtins->builtin(Builtins::LazyRecompile));
 }
 
 
@@ -5492,7 +5592,7 @@
 
 Object* JSFunction::SetInstancePrototype(Object* value) {
   ASSERT(value->IsJSObject());
-
+  Heap* heap = GetHeap();
   if (has_initial_map()) {
     initial_map()->set_prototype(value);
   } else {
@@ -5501,7 +5601,7 @@
     // prototype is put into the initial map where it belongs.
     set_prototype_or_initial_map(value);
   }
-  Heap::ClearInstanceofCache();
+  heap->ClearInstanceofCache();
   return value;
 }
 
@@ -5515,6 +5615,7 @@
   // used for constructing objects to the original object prototype.
   // See ECMA-262 13.2.2.
   if (!value->IsJSObject()) {
+    Heap* heap = GetHeap();
     // Copy the map so this does not affect unrelated functions.
     // Remove map transitions because they point to maps with a
     // different prototype.
@@ -5526,7 +5627,8 @@
     map()->set_constructor(value);
     map()->set_non_instance_prototype(true);
     construct_prototype =
-        Top::context()->global_context()->initial_object_prototype();
+        heap->isolate()->context()->global_context()->
+            initial_object_prototype();
   } else {
     map()->set_non_instance_prototype(false);
   }
@@ -5551,7 +5653,7 @@
   ASSERT(shared()->strict_mode() || map() == global_context->function_map());
 
   set_map(no_prototype_map);
-  set_prototype_or_initial_map(Heap::the_hole_value());
+  set_prototype_or_initial_map(GetHeap()->the_hole_value());
   return this;
 }
 
@@ -5573,13 +5675,17 @@
 }
 
 
-MaybeObject* Oddball::Initialize(const char* to_string, Object* to_number) {
+MaybeObject* Oddball::Initialize(const char* to_string,
+                                 Object* to_number,
+                                 byte kind) {
   Object* symbol;
-  { MaybeObject* maybe_symbol = Heap::LookupAsciiSymbol(to_string);
+  { MaybeObject* maybe_symbol =
+        Isolate::Current()->heap()->LookupAsciiSymbol(to_string);
     if (!maybe_symbol->ToObject(&symbol)) return maybe_symbol;
   }
   set_to_string(String::cast(symbol));
   set_to_number(to_number);
+  set_kind(kind);
   return this;
 }
 
@@ -5598,10 +5704,11 @@
 
 
 Object* SharedFunctionInfo::GetSourceCode() {
-  if (!HasSourceCode()) return Heap::undefined_value();
-  HandleScope scope;
+  Isolate* isolate = GetIsolate();
+  if (!HasSourceCode()) return isolate->heap()->undefined_value();
+  HandleScope scope(isolate);
   Object* source = Script::cast(script())->source();
-  return *SubString(Handle<String>(String::cast(source)),
+  return *SubString(Handle<String>(String::cast(source), isolate),
                     start_position(), end_position());
 }
 
@@ -5628,6 +5735,8 @@
 
 
 bool SharedFunctionInfo::CanGenerateInlineConstructor(Object* prototype) {
+  Heap* heap = GetHeap();
+
   // Check the basic conditions for generating inline constructor code.
   if (!FLAG_inline_new
       || !has_only_simple_this_property_assignments()
@@ -5644,7 +5753,7 @@
   // Traverse the proposed prototype chain looking for setters for properties of
   // the same names as are set by the inline constructor.
   for (Object* obj = prototype;
-       obj != Heap::null_value();
+       obj != heap->null_value();
        obj = obj->GetPrototype()) {
     JSObject* js_object = JSObject::cast(obj);
     for (int i = 0; i < this_property_assignments_count(); i++) {
@@ -5680,10 +5789,11 @@
 
 
 void SharedFunctionInfo::ClearThisPropertyAssignmentsInfo() {
+  Heap* heap = GetHeap();
   set_compiler_hints(BooleanBit::set(compiler_hints(),
                                      kHasOnlySimpleThisPropertyAssignments,
                                      false));
-  set_this_property_assignments(Heap::undefined_value());
+  set_this_property_assignments(heap->undefined_value());
   set_this_property_assignments_count(0);
 }
 
@@ -5828,9 +5938,10 @@
     set_construction_count(kGenerousAllocationCount);
   }
   set_initial_map(map);
-  ASSERT_EQ(Builtins::builtin(Builtins::JSConstructStubGeneric),
+  Builtins* builtins = map->heap()->isolate()->builtins();
+  ASSERT_EQ(builtins->builtin(Builtins::JSConstructStubGeneric),
             construct_stub());
-  set_construct_stub(Builtins::builtin(Builtins::JSConstructStubCountdown));
+  set_construct_stub(builtins->builtin(Builtins::JSConstructStubCountdown));
 }
 
 
@@ -5847,10 +5958,11 @@
   // then StartInobjectTracking will be called again the next time the
   // constructor is called. The countdown will continue and (possibly after
   // several more GCs) CompleteInobjectSlackTracking will eventually be called.
-  set_initial_map(Heap::raw_unchecked_undefined_value());
-  ASSERT_EQ(Builtins::builtin(Builtins::JSConstructStubCountdown),
+  set_initial_map(map->heap()->raw_unchecked_undefined_value());
+  Builtins* builtins = map->heap()->isolate()->builtins();
+  ASSERT_EQ(builtins->builtin(Builtins::JSConstructStubCountdown),
             *RawField(this, kConstructStubOffset));
-  set_construct_stub(Builtins::builtin(Builtins::JSConstructStubGeneric));
+  set_construct_stub(builtins->builtin(Builtins::JSConstructStubGeneric));
   // It is safe to clear the flag: it will be set again if the map is live.
   set_live_objects_may_exist(false);
 }
@@ -5863,9 +5975,10 @@
 
   // Resume inobject slack tracking.
   set_initial_map(map);
-  ASSERT_EQ(Builtins::builtin(Builtins::JSConstructStubGeneric),
+  Builtins* builtins = map->heap()->isolate()->builtins();
+  ASSERT_EQ(builtins->builtin(Builtins::JSConstructStubGeneric),
             *RawField(this, kConstructStubOffset));
-  set_construct_stub(Builtins::builtin(Builtins::JSConstructStubCountdown));
+  set_construct_stub(builtins->builtin(Builtins::JSConstructStubCountdown));
   // The map survived the gc, so there may be objects referencing it.
   set_live_objects_may_exist(true);
 }
@@ -5894,10 +6007,12 @@
   ASSERT(live_objects_may_exist() && IsInobjectSlackTrackingInProgress());
   Map* map = Map::cast(initial_map());
 
-  set_initial_map(Heap::undefined_value());
-  ASSERT_EQ(Builtins::builtin(Builtins::JSConstructStubCountdown),
+  Heap* heap = map->heap();
+  set_initial_map(heap->undefined_value());
+  Builtins* builtins = heap->isolate()->builtins();
+  ASSERT_EQ(builtins->builtin(Builtins::JSConstructStubCountdown),
             construct_stub());
-  set_construct_stub(Builtins::builtin(Builtins::JSConstructStubGeneric));
+  set_construct_stub(builtins->builtin(Builtins::JSConstructStubGeneric));
 
   int slack = map->unused_property_fields();
   map->TraverseTransitionTree(&GetMinInobjectSlack, &slack);
@@ -5954,8 +6069,7 @@
 
 
 void Code::InvalidateRelocation() {
-  HandleScope scope;
-  set_relocation_info(Heap::empty_byte_array());
+  set_relocation_info(GetHeap()->empty_byte_array());
 }
 
 
@@ -6401,11 +6515,12 @@
 
 MaybeObject* JSObject::SetFastElementsCapacityAndLength(int capacity,
                                                         int length) {
+  Heap* heap = GetHeap();
   // We should never end in here with a pixel or external array.
   ASSERT(!HasExternalArrayElements());
 
   Object* obj;
-  { MaybeObject* maybe_obj = Heap::AllocateFixedArrayWithHoles(capacity);
+  { MaybeObject* maybe_obj = heap->AllocateFixedArrayWithHoles(capacity);
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   FixedArray* elems = FixedArray::cast(obj);
@@ -6492,14 +6607,15 @@
 
 
 MaybeObject* JSArray::Initialize(int capacity) {
+  Heap* heap = GetHeap();
   ASSERT(capacity >= 0);
   set_length(Smi::FromInt(0));
   FixedArray* new_elements;
   if (capacity == 0) {
-    new_elements = Heap::empty_fixed_array();
+    new_elements = heap->empty_fixed_array();
   } else {
     Object* obj;
-    { MaybeObject* maybe_obj = Heap::AllocateFixedArrayWithHoles(capacity);
+    { MaybeObject* maybe_obj = heap->AllocateFixedArrayWithHoles(capacity);
       if (!maybe_obj->ToObject(&obj)) return maybe_obj;
     }
     new_elements = FixedArray::cast(obj);
@@ -6514,21 +6630,23 @@
   Handle<FixedArray> old_backing(FixedArray::cast(elements()));
   int old_size = old_backing->length();
   int new_size = required_size > old_size ? required_size : old_size;
-  Handle<FixedArray> new_backing = Factory::NewFixedArray(new_size);
+  Handle<FixedArray> new_backing = FACTORY->NewFixedArray(new_size);
   // Can't use this any more now because we may have had a GC!
   for (int i = 0; i < old_size; i++) new_backing->set(i, old_backing->get(i));
   self->SetContent(*new_backing);
 }
 
 
-static Failure* ArrayLengthRangeError() {
+static Failure* ArrayLengthRangeError(Heap* heap) {
   HandleScope scope;
-  return Top::Throw(*Factory::NewRangeError("invalid_array_length",
-                                            HandleVector<Object>(NULL, 0)));
+  return heap->isolate()->Throw(
+      *FACTORY->NewRangeError("invalid_array_length",
+          HandleVector<Object>(NULL, 0)));
 }
 
 
 MaybeObject* JSObject::SetElementsLength(Object* len) {
+  Heap* heap = GetHeap();
   // We should never end in here with a pixel or external array.
   ASSERT(AllowsSetElementsLength());
 
@@ -6536,7 +6654,7 @@
   Object* smi_length = Smi::FromInt(0);
   if (maybe_smi_length->ToObject(&smi_length) && smi_length->IsSmi()) {
     const int value = Smi::cast(smi_length)->value();
-    if (value < 0) return ArrayLengthRangeError();
+    if (value < 0) return ArrayLengthRangeError(heap);
     switch (GetElementsKind()) {
       case FAST_ELEMENTS: {
         int old_capacity = FixedArray::cast(elements())->length();
@@ -6602,14 +6720,14 @@
     if (len->ToArrayIndex(&length)) {
       return SetSlowElements(len);
     } else {
-      return ArrayLengthRangeError();
+      return ArrayLengthRangeError(heap);
     }
   }
 
   // len is not a number so make the array size one and
   // set only element to len.
   Object* obj;
-  { MaybeObject* maybe_obj = Heap::AllocateFixedArray(1);
+  { MaybeObject* maybe_obj = heap->AllocateFixedArray(1);
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   FixedArray::cast(obj)->set(0, len);
@@ -6621,6 +6739,7 @@
 
 MaybeObject* JSObject::SetPrototype(Object* value,
                                     bool skip_hidden_prototypes) {
+  Heap* heap = GetHeap();
   // Silently ignore the change if value is not a JSObject or null.
   // SpiderMonkey behaves this way.
   if (!value->IsJSObject() && !value->IsNull()) return value;
@@ -6629,12 +6748,12 @@
   // prototype cycles are prevented.
   // It is sufficient to validate that the receiver is not in the new prototype
   // chain.
-  for (Object* pt = value; pt != Heap::null_value(); pt = pt->GetPrototype()) {
+  for (Object* pt = value; pt != heap->null_value(); pt = pt->GetPrototype()) {
     if (JSObject::cast(pt) == this) {
       // Cycle detected.
       HandleScope scope;
-      return Top::Throw(*Factory::NewError("cyclic_proto",
-                                           HandleVector<Object>(NULL, 0)));
+      return heap->isolate()->Throw(
+          *FACTORY->NewError("cyclic_proto", HandleVector<Object>(NULL, 0)));
     }
   }
 
@@ -6659,7 +6778,7 @@
   Map::cast(new_map)->set_prototype(value);
   real_receiver->set_map(Map::cast(new_map));
 
-  Heap::ClearInstanceofCache();
+  heap->ClearInstanceofCache();
 
   return value;
 }
@@ -6714,29 +6833,31 @@
   if (this->IsStringObjectWithCharacterAt(index)) return true;
 
   Object* pt = GetPrototype();
-  if (pt == Heap::null_value()) return false;
+  if (pt->IsNull()) return false;
   return JSObject::cast(pt)->HasElementWithReceiver(receiver, index);
 }
 
 
 bool JSObject::HasElementWithInterceptor(JSObject* receiver, uint32_t index) {
+  Isolate* isolate = GetIsolate();
   // Make sure that the top context does not change when doing
   // callbacks or interceptor calls.
   AssertNoContextChange ncc;
-  HandleScope scope;
+  HandleScope scope(isolate);
   Handle<InterceptorInfo> interceptor(GetIndexedInterceptor());
   Handle<JSObject> receiver_handle(receiver);
   Handle<JSObject> holder_handle(this);
-  CustomArguments args(interceptor->data(), receiver, this);
+  CustomArguments args(isolate, interceptor->data(), receiver, this);
   v8::AccessorInfo info(args.end());
   if (!interceptor->query()->IsUndefined()) {
     v8::IndexedPropertyQuery query =
         v8::ToCData<v8::IndexedPropertyQuery>(interceptor->query());
-    LOG(ApiIndexedPropertyAccess("interceptor-indexed-has", this, index));
+    LOG(isolate,
+        ApiIndexedPropertyAccess("interceptor-indexed-has", this, index));
     v8::Handle<v8::Integer> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       result = query(index, info);
     }
     if (!result.IsEmpty()) {
@@ -6746,11 +6867,12 @@
   } else if (!interceptor->getter()->IsUndefined()) {
     v8::IndexedPropertyGetter getter =
         v8::ToCData<v8::IndexedPropertyGetter>(interceptor->getter());
-    LOG(ApiIndexedPropertyAccess("interceptor-indexed-has-get", this, index));
+    LOG(isolate,
+        ApiIndexedPropertyAccess("interceptor-indexed-has-get", this, index));
     v8::Handle<v8::Value> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       result = getter(index, info);
     }
     if (!result.IsEmpty()) return true;
@@ -6760,10 +6882,12 @@
 
 
 JSObject::LocalElementType JSObject::HasLocalElement(uint32_t index) {
+  Heap* heap = GetHeap();
+
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayIndexedAccess(this, index, v8::ACCESS_HAS)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_HAS);
+      !heap->isolate()->MayIndexedAccess(this, index, v8::ACCESS_HAS)) {
+    heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_HAS);
     return UNDEFINED_ELEMENT;
   }
 
@@ -6830,10 +6954,12 @@
 
 
 bool JSObject::HasElementWithReceiver(JSObject* receiver, uint32_t index) {
+  Heap* heap = GetHeap();
+
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayIndexedAccess(this, index, v8::ACCESS_HAS)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_HAS);
+      !heap->isolate()->MayIndexedAccess(this, index, v8::ACCESS_HAS)) {
+    heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_HAS);
     return false;
   }
 
@@ -6888,7 +7014,7 @@
   if (this->IsStringObjectWithCharacterAt(index)) return true;
 
   Object* pt = GetPrototype();
-  if (pt == Heap::null_value()) return false;
+  if (pt->IsNull()) return false;
   return JSObject::cast(pt)->HasElementWithReceiver(receiver, index);
 }
 
@@ -6897,26 +7023,28 @@
                                                  Object* value,
                                                  StrictModeFlag strict_mode,
                                                  bool check_prototype) {
+  Isolate* isolate = GetIsolate();
   // Make sure that the top context does not change when doing
   // callbacks or interceptor calls.
   AssertNoContextChange ncc;
-  HandleScope scope;
+  HandleScope scope(isolate);
   Handle<InterceptorInfo> interceptor(GetIndexedInterceptor());
   Handle<JSObject> this_handle(this);
-  Handle<Object> value_handle(value);
+  Handle<Object> value_handle(value, isolate);
   if (!interceptor->setter()->IsUndefined()) {
     v8::IndexedPropertySetter setter =
         v8::ToCData<v8::IndexedPropertySetter>(interceptor->setter());
-    LOG(ApiIndexedPropertyAccess("interceptor-indexed-set", this, index));
-    CustomArguments args(interceptor->data(), this, this);
+    LOG(isolate,
+        ApiIndexedPropertyAccess("interceptor-indexed-set", this, index));
+    CustomArguments args(isolate, interceptor->data(), this, this);
     v8::AccessorInfo info(args.end());
     v8::Handle<v8::Value> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       result = setter(index, v8::Utils::ToLocal(value_handle), info);
     }
-    RETURN_IF_SCHEDULED_EXCEPTION();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
     if (!result.IsEmpty()) return *value_handle;
   }
   MaybeObject* raw_result =
@@ -6924,7 +7052,7 @@
                                                 *value_handle,
                                                 strict_mode,
                                                 check_prototype);
-  RETURN_IF_SCHEDULED_EXCEPTION();
+  RETURN_IF_SCHEDULED_EXCEPTION(isolate);
   return raw_result;
 }
 
@@ -6933,6 +7061,7 @@
                                               Object* structure,
                                               uint32_t index,
                                               Object* holder) {
+  Isolate* isolate = GetIsolate();
   ASSERT(!structure->IsProxy());
 
   // api style callbacks.
@@ -6940,22 +7069,22 @@
     AccessorInfo* data = AccessorInfo::cast(structure);
     Object* fun_obj = data->getter();
     v8::AccessorGetter call_fun = v8::ToCData<v8::AccessorGetter>(fun_obj);
-    HandleScope scope;
+    HandleScope scope(isolate);
     Handle<JSObject> self(JSObject::cast(receiver));
     Handle<JSObject> holder_handle(JSObject::cast(holder));
-    Handle<Object> number = Factory::NewNumberFromUint(index);
-    Handle<String> key(Factory::NumberToString(number));
-    LOG(ApiNamedPropertyAccess("load", *self, *key));
-    CustomArguments args(data->data(), *self, *holder_handle);
+    Handle<Object> number = isolate->factory()->NewNumberFromUint(index);
+    Handle<String> key(isolate->factory()->NumberToString(number));
+    LOG(isolate, ApiNamedPropertyAccess("load", *self, *key));
+    CustomArguments args(isolate, data->data(), *self, *holder_handle);
     v8::AccessorInfo info(args.end());
     v8::Handle<v8::Value> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       result = call_fun(v8::Utils::ToLocal(key), info);
     }
-    RETURN_IF_SCHEDULED_EXCEPTION();
-    if (result.IsEmpty()) return Heap::undefined_value();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
+    if (result.IsEmpty()) return isolate->heap()->undefined_value();
     return *v8::Utils::OpenHandle(*result);
   }
 
@@ -6967,7 +7096,7 @@
                                                   JSFunction::cast(getter));
     }
     // Getter is not a function.
-    return Heap::undefined_value();
+    return isolate->heap()->undefined_value();
   }
 
   UNREACHABLE();
@@ -6979,12 +7108,13 @@
                                               uint32_t index,
                                               Object* value,
                                               JSObject* holder) {
-  HandleScope scope;
+  Isolate* isolate = GetIsolate();
+  HandleScope scope(isolate);
 
   // We should never get here to initialize a const with the hole
   // value since a const declaration would conflict with the setter.
   ASSERT(!value->IsTheHole());
-  Handle<Object> value_handle(value);
+  Handle<Object> value_handle(value, isolate);
 
   // To accommodate both the old and the new api we switch on the
   // data structure used to store the callbacks.  Eventually proxy
@@ -6997,19 +7127,19 @@
     Object* call_obj = data->setter();
     v8::AccessorSetter call_fun = v8::ToCData<v8::AccessorSetter>(call_obj);
     if (call_fun == NULL) return value;
-    Handle<Object> number = Factory::NewNumberFromUint(index);
-    Handle<String> key(Factory::NumberToString(number));
-    LOG(ApiNamedPropertyAccess("store", this, *key));
-    CustomArguments args(data->data(), this, JSObject::cast(holder));
+    Handle<Object> number = isolate->factory()->NewNumberFromUint(index);
+    Handle<String> key(isolate->factory()->NumberToString(number));
+    LOG(isolate, ApiNamedPropertyAccess("store", this, *key));
+    CustomArguments args(isolate, data->data(), this, JSObject::cast(holder));
     v8::AccessorInfo info(args.end());
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       call_fun(v8::Utils::ToLocal(key),
                v8::Utils::ToLocal(value_handle),
                info);
     }
-    RETURN_IF_SCHEDULED_EXCEPTION();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
     return *value_handle;
   }
 
@@ -7018,11 +7148,12 @@
     if (setter->IsJSFunction()) {
      return SetPropertyWithDefinedSetter(JSFunction::cast(setter), value);
     } else {
-      Handle<Object> holder_handle(holder);
-      Handle<Object> key(Factory::NewNumberFromUint(index));
+      Handle<Object> holder_handle(holder, isolate);
+      Handle<Object> key(isolate->factory()->NewNumberFromUint(index));
       Handle<Object> args[2] = { key, holder_handle };
-      return Top::Throw(*Factory::NewTypeError("no_setter_in_callback",
-                                               HandleVector(args, 2)));
+      return isolate->Throw(
+          *isolate->factory()->NewTypeError("no_setter_in_callback",
+                                            HandleVector(args, 2)));
     }
   }
 
@@ -7101,12 +7232,13 @@
                                   Object* value,
                                   StrictModeFlag strict_mode,
                                   bool check_prototype) {
+  Heap* heap = GetHeap();
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayIndexedAccess(this, index, v8::ACCESS_SET)) {
+      !heap->isolate()->MayIndexedAccess(this, index, v8::ACCESS_SET)) {
     HandleScope scope;
     Handle<Object> value_handle(value);
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_SET);
+    heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_SET);
     return *value_handle;
   }
 
@@ -7139,6 +7271,7 @@
                                                     Object* value,
                                                     StrictModeFlag strict_mode,
                                                     bool check_prototype) {
+  Isolate* isolate = GetIsolate();
   switch (GetElementsKind()) {
     case FAST_ELEMENTS:
       // Fast case.
@@ -7194,12 +7327,12 @@
           // If put fails instrict mode, throw exception.
           if (!dictionary->ValueAtPut(entry, value) &&
               strict_mode == kStrictMode) {
-            Handle<Object> number(Factory::NewNumberFromUint(index));
+            Handle<Object> number(isolate->factory()->NewNumberFromUint(index));
             Handle<Object> holder(this);
             Handle<Object> args[2] = { number, holder };
-            return Top::Throw(
-                *Factory::NewTypeError("strict_read_only_property",
-                                       HandleVector(args, 2)));
+            return isolate->Throw(
+                *isolate->factory()->NewTypeError("strict_read_only_property",
+                                                  HandleVector(args, 2)));
           }
         }
       } else {
@@ -7214,11 +7347,13 @@
         // When we set the is_extensible flag to false we always force
         // the element into dictionary mode (and force them to stay there).
         if (!map()->is_extensible()) {
-          Handle<Object> number(Factory::NewNumberFromUint(index));
-          Handle<String> index_string(Factory::NumberToString(number));
+          Handle<Object> number(isolate->factory()->NewNumberFromUint(index));
+          Handle<String> index_string(
+              isolate->factory()->NumberToString(number));
           Handle<Object> args[1] = { index_string };
-          return Top::Throw(*Factory::NewTypeError("object_not_extensible",
-                                                   HandleVector(args, 1)));
+          return isolate->Throw(
+              *isolate->factory()->NewTypeError("object_not_extensible",
+                                                HandleVector(args, 1)));
         }
         Object* result;
         { MaybeObject* maybe_result = dictionary->AtNumberPut(index, value);
@@ -7271,7 +7406,7 @@
   // All possible cases have been handled above. Add a return to avoid the
   // complaints from the compiler.
   UNREACHABLE();
-  return Heap::null_value();
+  return isolate->heap()->null_value();
 }
 
 
@@ -7284,7 +7419,7 @@
   if (index >= old_len && index != 0xffffffff) {
     Object* len;
     { MaybeObject* maybe_len =
-          Heap::NumberFromDouble(static_cast<double>(index) + 1);
+          GetHeap()->NumberFromDouble(static_cast<double>(index) + 1);
       if (!maybe_len->ToObject(&len)) return maybe_len;
     }
     set_length(len);
@@ -7295,6 +7430,7 @@
 
 MaybeObject* JSObject::GetElementPostInterceptor(Object* receiver,
                                                  uint32_t index) {
+  Heap* heap = GetHeap();
   // Get element works for both JSObject and JSArray since
   // JSArray::length cannot change.
   switch (GetElementsKind()) {
@@ -7343,17 +7479,18 @@
 
   // Continue searching via the prototype chain.
   Object* pt = GetPrototype();
-  if (pt == Heap::null_value()) return Heap::undefined_value();
+  if (pt->IsNull()) return heap->undefined_value();
   return pt->GetElementWithReceiver(receiver, index);
 }
 
 
 MaybeObject* JSObject::GetElementWithInterceptor(Object* receiver,
                                                  uint32_t index) {
+  Isolate* isolate = GetIsolate();
   // Make sure that the top context does not change when doing
   // callbacks or interceptor calls.
   AssertNoContextChange ncc;
-  HandleScope scope;
+  HandleScope scope(isolate);
   Handle<InterceptorInfo> interceptor(GetIndexedInterceptor());
   Handle<Object> this_handle(receiver);
   Handle<JSObject> holder_handle(this);
@@ -7361,33 +7498,35 @@
   if (!interceptor->getter()->IsUndefined()) {
     v8::IndexedPropertyGetter getter =
         v8::ToCData<v8::IndexedPropertyGetter>(interceptor->getter());
-    LOG(ApiIndexedPropertyAccess("interceptor-indexed-get", this, index));
-    CustomArguments args(interceptor->data(), receiver, this);
+    LOG(isolate,
+        ApiIndexedPropertyAccess("interceptor-indexed-get", this, index));
+    CustomArguments args(isolate, interceptor->data(), receiver, this);
     v8::AccessorInfo info(args.end());
     v8::Handle<v8::Value> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       result = getter(index, info);
     }
-    RETURN_IF_SCHEDULED_EXCEPTION();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
     if (!result.IsEmpty()) return *v8::Utils::OpenHandle(*result);
   }
 
   MaybeObject* raw_result =
       holder_handle->GetElementPostInterceptor(*this_handle, index);
-  RETURN_IF_SCHEDULED_EXCEPTION();
+  RETURN_IF_SCHEDULED_EXCEPTION(isolate);
   return raw_result;
 }
 
 
 MaybeObject* JSObject::GetElementWithReceiver(Object* receiver,
                                               uint32_t index) {
+  Heap* heap = GetHeap();
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayIndexedAccess(this, index, v8::ACCESS_GET)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_GET);
-    return Heap::undefined_value();
+      !heap->isolate()->MayIndexedAccess(this, index, v8::ACCESS_GET)) {
+    heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_GET);
+    return heap->undefined_value();
   }
 
   if (HasIndexedInterceptor()) {
@@ -7438,7 +7577,7 @@
   }
 
   Object* pt = GetPrototype();
-  if (pt == Heap::null_value()) return Heap::undefined_value();
+  if (pt == heap->null_value()) return heap->undefined_value();
   return pt->GetElementWithReceiver(receiver, index);
 }
 
@@ -7493,7 +7632,7 @@
       ExternalIntArray* array = ExternalIntArray::cast(elements());
       if (index < static_cast<uint32_t>(array->length())) {
         int32_t value = array->get(index);
-        return Heap::NumberFromInt32(value);
+        return GetHeap()->NumberFromInt32(value);
       }
       break;
     }
@@ -7502,7 +7641,7 @@
           ExternalUnsignedIntArray::cast(elements());
       if (index < static_cast<uint32_t>(array->length())) {
         uint32_t value = array->get(index);
-        return Heap::NumberFromUint32(value);
+        return GetHeap()->NumberFromUint32(value);
       }
       break;
     }
@@ -7510,7 +7649,7 @@
       ExternalFloatArray* array = ExternalFloatArray::cast(elements());
       if (index < static_cast<uint32_t>(array->length())) {
         float value = array->get(index);
-        return Heap::AllocateHeapNumber(value);
+        return GetHeap()->AllocateHeapNumber(value);
       }
       break;
     }
@@ -7519,7 +7658,7 @@
       UNREACHABLE();
       break;
   }
-  return Heap::undefined_value();
+  return GetHeap()->undefined_value();
 }
 
 
@@ -7664,6 +7803,7 @@
     JSObject* receiver,
     String* name,
     PropertyAttributes* attributes) {
+  Heap* heap = GetHeap();
   // Check local property in holder, ignore interceptor.
   LookupResult result;
   LocalLookupRealNamedProperty(name, &result);
@@ -7673,7 +7813,7 @@
   // Continue searching via the prototype chain.
   Object* pt = GetPrototype();
   *attributes = ABSENT;
-  if (pt == Heap::null_value()) return Heap::undefined_value();
+  if (pt->IsNull()) return heap->undefined_value();
   return pt->GetPropertyWithReceiver(receiver, name, attributes);
 }
 
@@ -7682,13 +7822,14 @@
     JSObject* receiver,
     String* name,
     PropertyAttributes* attributes) {
+  Heap* heap = GetHeap();
   // Check local property in holder, ignore interceptor.
   LookupResult result;
   LocalLookupRealNamedProperty(name, &result);
   if (result.IsProperty()) {
     return GetProperty(receiver, &result, name, attributes);
   }
-  return Heap::undefined_value();
+  return heap->undefined_value();
 }
 
 
@@ -7696,8 +7837,9 @@
     JSObject* receiver,
     String* name,
     PropertyAttributes* attributes) {
+  Isolate* isolate = GetIsolate();
   InterceptorInfo* interceptor = GetNamedInterceptor();
-  HandleScope scope;
+  HandleScope scope(isolate);
   Handle<JSObject> receiver_handle(receiver);
   Handle<JSObject> holder_handle(this);
   Handle<String> name_handle(name);
@@ -7705,16 +7847,17 @@
   if (!interceptor->getter()->IsUndefined()) {
     v8::NamedPropertyGetter getter =
         v8::ToCData<v8::NamedPropertyGetter>(interceptor->getter());
-    LOG(ApiNamedPropertyAccess("interceptor-named-get", *holder_handle, name));
-    CustomArguments args(interceptor->data(), receiver, this);
+    LOG(isolate,
+        ApiNamedPropertyAccess("interceptor-named-get", *holder_handle, name));
+    CustomArguments args(isolate, interceptor->data(), receiver, this);
     v8::AccessorInfo info(args.end());
     v8::Handle<v8::Value> result;
     {
       // Leaving JavaScript.
-      VMState state(EXTERNAL);
+      VMState state(isolate, EXTERNAL);
       result = getter(v8::Utils::ToLocal(name_handle), info);
     }
-    RETURN_IF_SCHEDULED_EXCEPTION();
+    RETURN_IF_SCHEDULED_EXCEPTION(isolate);
     if (!result.IsEmpty()) {
       *attributes = NONE;
       return *v8::Utils::OpenHandle(*result);
@@ -7725,16 +7868,17 @@
       *receiver_handle,
       *name_handle,
       attributes);
-  RETURN_IF_SCHEDULED_EXCEPTION();
+  RETURN_IF_SCHEDULED_EXCEPTION(isolate);
   return result;
 }
 
 
 bool JSObject::HasRealNamedProperty(String* key) {
+  Heap* heap = GetHeap();
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayNamedAccess(this, key, v8::ACCESS_HAS)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_HAS);
+      !heap->isolate()->MayNamedAccess(this, key, v8::ACCESS_HAS)) {
+    heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_HAS);
     return false;
   }
 
@@ -7745,10 +7889,11 @@
 
 
 bool JSObject::HasRealElementProperty(uint32_t index) {
+  Heap* heap = GetHeap();
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayIndexedAccess(this, index, v8::ACCESS_HAS)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_HAS);
+      !heap->isolate()->MayIndexedAccess(this, index, v8::ACCESS_HAS)) {
+    heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_HAS);
     return false;
   }
 
@@ -7788,15 +7933,16 @@
   }
   // All possibilities have been handled above already.
   UNREACHABLE();
-  return Heap::null_value();
+  return heap->null_value();
 }
 
 
 bool JSObject::HasRealNamedCallbackProperty(String* key) {
+  Heap* heap = GetHeap();
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
-      !Top::MayNamedAccess(this, key, v8::ACCESS_HAS)) {
-    Top::ReportFailedAccessCheck(this, v8::ACCESS_HAS);
+      !heap->isolate()->MayNamedAccess(this, key, v8::ACCESS_HAS)) {
+    heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_HAS);
     return false;
   }
 
@@ -8059,51 +8205,6 @@
 }
 
 
-bool NumberDictionaryShape::IsMatch(uint32_t key, Object* other) {
-  ASSERT(other->IsNumber());
-  return key == static_cast<uint32_t>(other->Number());
-}
-
-
-uint32_t NumberDictionaryShape::Hash(uint32_t key) {
-  return ComputeIntegerHash(key);
-}
-
-
-uint32_t NumberDictionaryShape::HashForObject(uint32_t key, Object* other) {
-  ASSERT(other->IsNumber());
-  return ComputeIntegerHash(static_cast<uint32_t>(other->Number()));
-}
-
-
-MaybeObject* NumberDictionaryShape::AsObject(uint32_t key) {
-  return Heap::NumberFromUint32(key);
-}
-
-
-bool StringDictionaryShape::IsMatch(String* key, Object* other) {
-  // We know that all entries in a hash table had their hash keys created.
-  // Use that knowledge to have fast failure.
-  if (key->Hash() != String::cast(other)->Hash()) return false;
-  return key->Equals(String::cast(other));
-}
-
-
-uint32_t StringDictionaryShape::Hash(String* key) {
-  return key->Hash();
-}
-
-
-uint32_t StringDictionaryShape::HashForObject(String* key, Object* other) {
-  return String::cast(other)->Hash();
-}
-
-
-MaybeObject* StringDictionaryShape::AsObject(String* key) {
-  return key;
-}
-
-
 // StringKey simply carries a string object as key.
 class StringKey : public HashTableKey {
  public:
@@ -8186,7 +8287,7 @@
 
   MUST_USE_RESULT MaybeObject* AsObject() {
     Object* obj;
-    { MaybeObject* maybe_obj = Heap::AllocateFixedArray(3);
+    { MaybeObject* maybe_obj = source_->GetHeap()->AllocateFixedArray(3);
       if (!maybe_obj->ToObject(&obj)) return maybe_obj;
     }
     FixedArray* pair = FixedArray::cast(obj);
@@ -8270,7 +8371,8 @@
 
   MaybeObject* AsObject() {
     if (hash_field_ == 0) Hash();
-    return Heap::AllocateSymbol(string_, chars_, hash_field_);
+    return Isolate::Current()->heap()->AllocateSymbol(
+        string_, chars_, hash_field_);
   }
 
   Vector<const char> string_;
@@ -8337,7 +8439,7 @@
 
   MaybeObject* AsObject() {
     if (hash_field_ == 0) Hash();
-    return Heap::AllocateAsciiSymbol(string_, hash_field_);
+    return HEAP->AllocateAsciiSymbol(string_, hash_field_);
   }
 };
 
@@ -8353,7 +8455,7 @@
 
   MaybeObject* AsObject() {
     if (hash_field_ == 0) Hash();
-    return Heap::AllocateTwoByteSymbol(string_, hash_field_);
+    return HEAP->AllocateTwoByteSymbol(string_, hash_field_);
   }
 };
 
@@ -8361,7 +8463,8 @@
 // SymbolKey carries a string/symbol object as key.
 class SymbolKey : public HashTableKey {
  public:
-  explicit SymbolKey(String* string) : string_(string) { }
+  explicit SymbolKey(String* string)
+      : string_(string) { }
 
   bool IsMatch(Object* string) {
     return String::cast(string)->Equals(string_);
@@ -8377,8 +8480,9 @@
     // Attempt to flatten the string, so that symbols will most often
     // be flat strings.
     string_ = string_->TryFlattenGetString();
+    Heap* heap = string_->GetHeap();
     // Transform string to symbol if possible.
-    Map* map = Heap::SymbolMapForString(string_);
+    Map* map = heap->SymbolMapForString(string_);
     if (map != NULL) {
       string_->set_map(map);
       ASSERT(string_->IsSymbol());
@@ -8386,7 +8490,7 @@
     }
     // Otherwise allocate a new symbol.
     StringInputBuffer buffer(string_);
-    return Heap::AllocateInternalSymbol(&buffer,
+    return heap->AllocateInternalSymbol(&buffer,
                                         string_->length(),
                                         string_->hash_field());
   }
@@ -8425,8 +8529,8 @@
   }
 
   Object* obj;
-  { MaybeObject* maybe_obj =
-        Heap::AllocateHashTable(EntryToIndex(capacity), pretenure);
+  { MaybeObject* maybe_obj = Isolate::Current()->heap()->
+        AllocateHashTable(EntryToIndex(capacity), pretenure);
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   HashTable::cast(obj)->SetNumberOfElements(0);
@@ -8437,23 +8541,6 @@
 
 
 // Find entry for key otherwise return kNotFound.
-template<typename Shape, typename Key>
-int HashTable<Shape, Key>::FindEntry(Key key) {
-  uint32_t capacity = Capacity();
-  uint32_t entry = FirstProbe(Shape::Hash(key), capacity);
-  uint32_t count = 1;
-  // EnsureCapacity will guarantee the hash table is never full.
-  while (true) {
-    Object* element = KeyAt(entry);
-    if (element->IsUndefined()) break;  // Empty entry.
-    if (!element->IsNull() && Shape::IsMatch(key, element)) return entry;
-    entry = NextProbe(entry, count++, capacity);
-  }
-  return kNotFound;
-}
-
-
-// Find entry for key otherwise return kNotFound.
 int StringDictionary::FindEntry(String* key) {
   if (!key->IsSymbol()) {
     return HashTable<StringDictionaryShape, String*>::FindEntry(key);
@@ -8495,6 +8582,7 @@
 
 template<typename Shape, typename Key>
 MaybeObject* HashTable<Shape, Key>::EnsureCapacity(int n, Key key) {
+  Heap* heap = GetHeap();
   int capacity = Capacity();
   int nof = NumberOfElements() + n;
   int nod = NumberOfDeletedElements();
@@ -8508,7 +8596,7 @@
 
   const int kMinCapacityForPretenure = 256;
   bool pretenure =
-      (capacity > kMinCapacityForPretenure) && !Heap::InNewSpace(this);
+      (capacity > kMinCapacityForPretenure) && !heap->InNewSpace(this);
   Object* obj;
   { MaybeObject* maybe_obj =
         Allocate(nof * 2, pretenure ? TENURED : NOT_TENURED);
@@ -8640,6 +8728,7 @@
 // Collates undefined and unexisting elements below limit from position
 // zero of the elements. The object stays in Dictionary mode.
 MaybeObject* JSObject::PrepareSlowElementsForSort(uint32_t limit) {
+  Heap* heap = GetHeap();
   ASSERT(HasDictionaryElements());
   // Must stay in dictionary mode, either because of requires_slow_elements,
   // or because we are not going to sort (and therefore compact) all of the
@@ -8649,7 +8738,7 @@
   if (limit > static_cast<uint32_t>(Smi::kMaxValue)) {
     // Allocate space for result before we start mutating the object.
     Object* new_double;
-    { MaybeObject* maybe_new_double = Heap::AllocateHeapNumber(0.0);
+    { MaybeObject* maybe_new_double = heap->AllocateHeapNumber(0.0);
       if (!maybe_new_double->ToObject(&new_double)) return maybe_new_double;
     }
     result_double = HeapNumber::cast(new_double);
@@ -8715,7 +8804,7 @@
       // allocation. Bailout.
       return Smi::FromInt(-1);
     }
-    new_dict->AddNumberEntry(pos, Heap::undefined_value(), no_details)->
+    new_dict->AddNumberEntry(pos, heap->undefined_value(), no_details)->
         ToObjectUnchecked();
     pos++;
     undefs--;
@@ -8738,6 +8827,7 @@
 // If the object is in dictionary mode, it is converted to fast elements
 // mode.
 MaybeObject* JSObject::PrepareElementsForSort(uint32_t limit) {
+  Heap* heap = GetHeap();
   ASSERT(!HasExternalArrayElements());
 
   if (HasDictionaryElements()) {
@@ -8756,10 +8846,10 @@
     }
     Map* new_map = Map::cast(obj);
 
-    PretenureFlag tenure = Heap::InNewSpace(this) ? NOT_TENURED: TENURED;
+    PretenureFlag tenure = heap->InNewSpace(this) ? NOT_TENURED: TENURED;
     Object* new_array;
     { MaybeObject* maybe_new_array =
-          Heap::AllocateFixedArray(dict->NumberOfElements(), tenure);
+          heap->AllocateFixedArray(dict->NumberOfElements(), tenure);
       if (!maybe_new_array->ToObject(&new_array)) return maybe_new_array;
     }
     FixedArray* fast_elements = FixedArray::cast(new_array);
@@ -8792,7 +8882,7 @@
     // Pessimistically allocate space for return value before
     // we start mutating the array.
     Object* new_double;
-    { MaybeObject* maybe_new_double = Heap::AllocateHeapNumber(0.0);
+    { MaybeObject* maybe_new_double = heap->AllocateHeapNumber(0.0);
       if (!maybe_new_double->ToObject(&new_double)) return maybe_new_double;
     }
     result_double = HeapNumber::cast(new_double);
@@ -8886,7 +8976,8 @@
 
 
 template<typename ExternalArrayClass, typename ValueType>
-static MaybeObject* ExternalArrayIntSetter(ExternalArrayClass* receiver,
+static MaybeObject* ExternalArrayIntSetter(Heap* heap,
+                                           ExternalArrayClass* receiver,
                                            uint32_t index,
                                            Object* value) {
   ValueType cast_value = 0;
@@ -8904,45 +8995,46 @@
     }
     receiver->set(index, cast_value);
   }
-  return Heap::NumberFromInt32(cast_value);
+  return heap->NumberFromInt32(cast_value);
 }
 
 
 MaybeObject* ExternalByteArray::SetValue(uint32_t index, Object* value) {
   return ExternalArrayIntSetter<ExternalByteArray, int8_t>
-      (this, index, value);
+      (GetHeap(), this, index, value);
 }
 
 
 MaybeObject* ExternalUnsignedByteArray::SetValue(uint32_t index,
                                                  Object* value) {
   return ExternalArrayIntSetter<ExternalUnsignedByteArray, uint8_t>
-      (this, index, value);
+      (GetHeap(), this, index, value);
 }
 
 
 MaybeObject* ExternalShortArray::SetValue(uint32_t index,
                                           Object* value) {
   return ExternalArrayIntSetter<ExternalShortArray, int16_t>
-      (this, index, value);
+      (GetHeap(), this, index, value);
 }
 
 
 MaybeObject* ExternalUnsignedShortArray::SetValue(uint32_t index,
                                                   Object* value) {
   return ExternalArrayIntSetter<ExternalUnsignedShortArray, uint16_t>
-      (this, index, value);
+      (GetHeap(), this, index, value);
 }
 
 
 MaybeObject* ExternalIntArray::SetValue(uint32_t index, Object* value) {
   return ExternalArrayIntSetter<ExternalIntArray, int32_t>
-      (this, index, value);
+      (GetHeap(), this, index, value);
 }
 
 
 MaybeObject* ExternalUnsignedIntArray::SetValue(uint32_t index, Object* value) {
   uint32_t cast_value = 0;
+  Heap* heap = GetHeap();
   if (index < static_cast<uint32_t>(length())) {
     if (value->IsSmi()) {
       int int_value = Smi::cast(value)->value();
@@ -8957,12 +9049,13 @@
     }
     set(index, cast_value);
   }
-  return Heap::NumberFromUint32(cast_value);
+  return heap->NumberFromUint32(cast_value);
 }
 
 
 MaybeObject* ExternalFloatArray::SetValue(uint32_t index, Object* value) {
   float cast_value = 0;
+  Heap* heap = GetHeap();
   if (index < static_cast<uint32_t>(length())) {
     if (value->IsSmi()) {
       int int_value = Smi::cast(value)->value();
@@ -8977,7 +9070,7 @@
     }
     set(index, cast_value);
   }
-  return Heap::AllocateHeapNumber(cast_value);
+  return heap->AllocateHeapNumber(cast_value);
 }
 
 
@@ -8990,11 +9083,12 @@
 
 MaybeObject* GlobalObject::EnsurePropertyCell(String* name) {
   ASSERT(!HasFastProperties());
+  Heap* heap = GetHeap();
   int entry = property_dictionary()->FindEntry(name);
   if (entry == StringDictionary::kNotFound) {
     Object* cell;
     { MaybeObject* maybe_cell =
-          Heap::AllocateJSGlobalPropertyCell(Heap::the_hole_value());
+          heap->AllocateJSGlobalPropertyCell(heap->the_hole_value());
       if (!maybe_cell->ToObject(&cell)) return maybe_cell;
     }
     PropertyDetails details(NONE, NORMAL);
@@ -9166,9 +9260,10 @@
 
 
 Object* CompilationCacheTable::Lookup(String* src) {
+  Heap* heap = GetHeap();
   StringKey key(src);
   int entry = FindEntry(&key);
-  if (entry == kNotFound) return Heap::undefined_value();
+  if (entry == kNotFound) return heap->undefined_value();
   return get(EntryToIndex(entry) + 1);
 }
 
@@ -9178,16 +9273,17 @@
                                           StrictModeFlag strict_mode) {
   StringSharedKey key(src, context->closure()->shared(), strict_mode);
   int entry = FindEntry(&key);
-  if (entry == kNotFound) return Heap::undefined_value();
+  if (entry == kNotFound) return GetHeap()->undefined_value();
   return get(EntryToIndex(entry) + 1);
 }
 
 
 Object* CompilationCacheTable::LookupRegExp(String* src,
                                             JSRegExp::Flags flags) {
+  Heap* heap = GetHeap();
   RegExpKey key(src, flags);
   int entry = FindEntry(&key);
-  if (entry == kNotFound) return Heap::undefined_value();
+  if (entry == kNotFound) return heap->undefined_value();
   return get(EntryToIndex(entry) + 1);
 }
 
@@ -9258,12 +9354,13 @@
 
 
 void CompilationCacheTable::Remove(Object* value) {
+  Object* null_value = GetHeap()->null_value();
   for (int entry = 0, size = Capacity(); entry < size; entry++) {
     int entry_index = EntryToIndex(entry);
     int value_index = entry_index + 1;
     if (get(value_index) == value) {
-      fast_set(this, entry_index, Heap::null_value());
-      fast_set(this, value_index, Heap::null_value());
+      fast_set(this, entry_index, null_value);
+      fast_set(this, value_index, null_value);
       ElementRemoved();
     }
   }
@@ -9306,9 +9403,10 @@
 
 
 Object* MapCache::Lookup(FixedArray* array) {
+  Heap* heap = GetHeap();
   SymbolsKey key(array);
   int entry = FindEntry(&key);
-  if (entry == kNotFound) return Heap::undefined_value();
+  if (entry == kNotFound) return heap->undefined_value();
   return get(EntryToIndex(entry) + 1);
 }
 
@@ -9345,11 +9443,12 @@
 
 template<typename Shape, typename Key>
 MaybeObject* Dictionary<Shape, Key>::GenerateNewEnumerationIndices() {
+  Heap* heap = Dictionary<Shape, Key>::GetHeap();
   int length = HashTable<Shape, Key>::NumberOfElements();
 
   // Allocate and initialize iteration order array.
   Object* obj;
-  { MaybeObject* maybe_obj = Heap::AllocateFixedArray(length);
+  { MaybeObject* maybe_obj = heap->AllocateFixedArray(length);
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   FixedArray* iteration_order = FixedArray::cast(obj);
@@ -9358,7 +9457,7 @@
   }
 
   // Allocate array with enumeration order.
-  { MaybeObject* maybe_obj = Heap::AllocateFixedArray(length);
+  { MaybeObject* maybe_obj = heap->AllocateFixedArray(length);
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   FixedArray* enumeration_order = FixedArray::cast(obj);
@@ -9419,8 +9518,9 @@
   // Do nothing if the interval [from, to) is empty.
   if (from >= to) return;
 
+  Heap* heap = GetHeap();
   int removed_entries = 0;
-  Object* sentinel = Heap::null_value();
+  Object* sentinel = heap->null_value();
   int capacity = Capacity();
   for (int i = 0; i < capacity; i++) {
     Object* key = KeyAt(i);
@@ -9441,14 +9541,15 @@
 template<typename Shape, typename Key>
 Object* Dictionary<Shape, Key>::DeleteProperty(int entry,
                                                JSObject::DeleteMode mode) {
+  Heap* heap = Dictionary<Shape, Key>::GetHeap();
   PropertyDetails details = DetailsAt(entry);
   // Ignore attributes if forcing a deletion.
   if (details.IsDontDelete() && mode != JSObject::FORCE_DELETION) {
-    return Heap::false_value();
+    return heap->false_value();
   }
-  SetEntry(entry, Heap::null_value(), Heap::null_value(), Smi::FromInt(0));
+  SetEntry(entry, heap->null_value(), heap->null_value(), Smi::FromInt(0));
   HashTable<Shape, Key>::ElementRemoved();
-  return Heap::true_value();
+  return heap->true_value();
 }
 
 
@@ -9661,6 +9762,7 @@
 // Backwards lookup (slow).
 template<typename Shape, typename Key>
 Object* Dictionary<Shape, Key>::SlowReverseLookup(Object* value) {
+  Heap* heap = Dictionary<Shape, Key>::GetHeap();
   int capacity = HashTable<Shape, Key>::Capacity();
   for (int i = 0; i < capacity; i++) {
     Object* k =  HashTable<Shape, Key>::KeyAt(i);
@@ -9672,12 +9774,13 @@
       if (e == value) return k;
     }
   }
-  return Heap::undefined_value();
+  return heap->undefined_value();
 }
 
 
 MaybeObject* StringDictionary::TransformPropertiesToFastFor(
     JSObject* obj, int unused_property_fields) {
+  Heap* heap = GetHeap();
   // Make sure we preserve dictionary representation if there are too many
   // descriptors.
   if (NumberOfElements() > DescriptorArray::kMaxNumberOfDescriptors) return obj;
@@ -9707,7 +9810,7 @@
       ASSERT(type != FIELD);
       instance_descriptor_length++;
       if (type == NORMAL &&
-          (!value->IsJSFunction() || Heap::InNewSpace(value))) {
+          (!value->IsJSFunction() || heap->InNewSpace(value))) {
         number_of_fields += 1;
       }
     }
@@ -9735,7 +9838,7 @@
   // Allocate the fixed array for the fields.
   Object* fields;
   { MaybeObject* maybe_fields =
-        Heap::AllocateFixedArray(number_of_allocated_fields);
+        heap->AllocateFixedArray(number_of_allocated_fields);
     if (!maybe_fields->ToObject(&fields)) return maybe_fields;
   }
 
@@ -9748,13 +9851,13 @@
       Object* value = ValueAt(i);
       // Ensure the key is a symbol before writing into the instance descriptor.
       Object* key;
-      { MaybeObject* maybe_key = Heap::LookupSymbol(String::cast(k));
+      { MaybeObject* maybe_key = heap->LookupSymbol(String::cast(k));
         if (!maybe_key->ToObject(&key)) return maybe_key;
       }
       PropertyDetails details = DetailsAt(i);
       PropertyType type = details.type();
 
-      if (value->IsJSFunction() && !Heap::InNewSpace(value)) {
+      if (value->IsJSFunction() && !heap->InNewSpace(value)) {
         ConstantFunctionDescriptor d(String::cast(key),
                                      JSFunction::cast(value),
                                      details.attributes(),
@@ -9825,11 +9928,12 @@
 
 // Get the break point info object for this code position.
 Object* DebugInfo::GetBreakPointInfo(int code_position) {
+  Heap* heap = GetHeap();
   // Find the index of the break point info object for this code position.
   int index = GetBreakPointInfoIndex(code_position);
 
   // Return the break point info object if any.
-  if (index == kNoBreakPointInfo) return Heap::undefined_value();
+  if (index == kNoBreakPointInfo) return heap->undefined_value();
   return BreakPointInfo::cast(break_points()->get(index));
 }
 
@@ -9851,6 +9955,7 @@
                               int source_position,
                               int statement_position,
                               Handle<Object> break_point_object) {
+  Isolate* isolate = Isolate::Current();
   Handle<Object> break_point_info(debug_info->GetBreakPointInfo(code_position));
   if (!break_point_info->IsUndefined()) {
     BreakPointInfo::SetBreakPoint(
@@ -9873,8 +9978,9 @@
     Handle<FixedArray> old_break_points =
         Handle<FixedArray>(FixedArray::cast(debug_info->break_points()));
     Handle<FixedArray> new_break_points =
-        Factory::NewFixedArray(old_break_points->length() +
-                               Debug::kEstimatedNofBreakPointsInFunction);
+        isolate->factory()->NewFixedArray(
+            old_break_points->length() +
+            Debug::kEstimatedNofBreakPointsInFunction);
 
     debug_info->set_break_points(*new_break_points);
     for (int i = 0; i < old_break_points->length(); i++) {
@@ -9885,13 +9991,14 @@
   ASSERT(index != kNoBreakPointInfo);
 
   // Allocate new BreakPointInfo object and set the break point.
-  Handle<BreakPointInfo> new_break_point_info =
-      Handle<BreakPointInfo>::cast(Factory::NewStruct(BREAK_POINT_INFO_TYPE));
+  Handle<BreakPointInfo> new_break_point_info = Handle<BreakPointInfo>::cast(
+      isolate->factory()->NewStruct(BREAK_POINT_INFO_TYPE));
   new_break_point_info->set_code_position(Smi::FromInt(code_position));
   new_break_point_info->set_source_position(Smi::FromInt(source_position));
   new_break_point_info->
       set_statement_position(Smi::FromInt(statement_position));
-  new_break_point_info->set_break_point_objects(Heap::undefined_value());
+  new_break_point_info->set_break_point_objects(
+      isolate->heap()->undefined_value());
   BreakPointInfo::SetBreakPoint(new_break_point_info, break_point_object);
   debug_info->break_points()->set(index, *new_break_point_info);
 }
@@ -9899,9 +10006,10 @@
 
 // Get the break point objects for a code position.
 Object* DebugInfo::GetBreakPointObjects(int code_position) {
+  Heap* heap = GetHeap();
   Object* break_point_info = GetBreakPointInfo(code_position);
   if (break_point_info->IsUndefined()) {
-    return Heap::undefined_value();
+    return heap->undefined_value();
   }
   return BreakPointInfo::cast(break_point_info)->break_point_objects();
 }
@@ -9924,7 +10032,8 @@
 
 Object* DebugInfo::FindBreakPointInfo(Handle<DebugInfo> debug_info,
                                       Handle<Object> break_point_object) {
-  if (debug_info->break_points()->IsUndefined()) return Heap::undefined_value();
+  Heap* heap = Isolate::Current()->heap();
+  if (debug_info->break_points()->IsUndefined()) return heap->undefined_value();
   for (int i = 0; i < debug_info->break_points()->length(); i++) {
     if (!debug_info->break_points()->get(i)->IsUndefined()) {
       Handle<BreakPointInfo> break_point_info =
@@ -9936,7 +10045,7 @@
       }
     }
   }
-  return Heap::undefined_value();
+  return heap->undefined_value();
 }
 
 
@@ -9960,12 +10069,14 @@
 // Remove the specified break point object.
 void BreakPointInfo::ClearBreakPoint(Handle<BreakPointInfo> break_point_info,
                                      Handle<Object> break_point_object) {
+  Isolate* isolate = Isolate::Current();
   // If there are no break points just ignore.
   if (break_point_info->break_point_objects()->IsUndefined()) return;
   // If there is a single break point clear it if it is the same.
   if (!break_point_info->break_point_objects()->IsFixedArray()) {
     if (break_point_info->break_point_objects() == *break_point_object) {
-      break_point_info->set_break_point_objects(Heap::undefined_value());
+      break_point_info->set_break_point_objects(
+          isolate->heap()->undefined_value());
     }
     return;
   }
@@ -9975,7 +10086,7 @@
       Handle<FixedArray>(
           FixedArray::cast(break_point_info->break_point_objects()));
   Handle<FixedArray> new_array =
-      Factory::NewFixedArray(old_array->length() - 1);
+      isolate->factory()->NewFixedArray(old_array->length() - 1);
   int found_count = 0;
   for (int i = 0; i < old_array->length(); i++) {
     if (old_array->get(i) == *break_point_object) {
@@ -10002,7 +10113,7 @@
   if (break_point_info->break_point_objects() == *break_point_object) return;
   // If there was one break point object before replace with array.
   if (!break_point_info->break_point_objects()->IsFixedArray()) {
-    Handle<FixedArray> array = Factory::NewFixedArray(2);
+    Handle<FixedArray> array = FACTORY->NewFixedArray(2);
     array->set(0, break_point_info->break_point_objects());
     array->set(1, *break_point_object);
     break_point_info->set_break_point_objects(*array);
@@ -10013,7 +10124,7 @@
       Handle<FixedArray>(
           FixedArray::cast(break_point_info->break_point_objects()));
   Handle<FixedArray> new_array =
-      Factory::NewFixedArray(old_array->length() + 1);
+      FACTORY->NewFixedArray(old_array->length() + 1);
   for (int i = 0; i < old_array->length(); i++) {
     // If the break point was there before just ignore.
     if (old_array->get(i) == *break_point_object) return;