Introduce MaybeHandle to police exception checking in handlified code.

src/objects.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5513 matching lines @@
         attrs |= READ_ONLY;
       }
       details = details.CopyAddAttributes(
           static_cast<PropertyAttributes>(attrs));
       dictionary->DetailsAtPut(i, details);
     }
   }
 }
 
 
-Handle<Object> JSObject::Freeze(Handle<JSObject> object) {
+MaybeHandle<Object> JSObject::Freeze(Handle<JSObject> object) {
   // Freezing sloppy arguments should be handled elsewhere.
   ASSERT(!object->HasSloppyArgumentsElements());
   ASSERT(!object->map()->is_observed());
 
   if (object->map()->is_frozen()) return object;
 
   Isolate* isolate = object->GetIsolate();
   if (object->IsAccessCheckNeeded() &&
       !isolate->MayNamedAccessWrapper(object,
                                       isolate->factory()->undefined_value(),
                                       v8::ACCESS_KEYS)) {
     isolate->ReportFailedAccessCheckWrapper(object, v8::ACCESS_KEYS);
-    RETURN_HANDLE_IF_SCHEDULED_EXCEPTION(isolate, Object);
+    RETURN_EXCEPTION_IF_SCHEDULED_EXCEPTION(isolate, Object);
     return isolate->factory()->false_value();
   }
 
   if (object->IsJSGlobalProxy()) {
     Handle<Object> proto(object->GetPrototype(), isolate);
     if (proto->IsNull()) return object;
     ASSERT(proto->IsJSGlobalObject());
     return Freeze(Handle<JSObject>::cast(proto));
   }
 
   // It's not possible to freeze objects with external array elements
   if (object->HasExternalArrayElements() ||
       object->HasFixedTypedArrayElements()) {
     Handle<Object> error  =
         isolate->factory()->NewTypeError(
             "cant_prevent_ext_external_array_elements",
             HandleVector(&object, 1));
-    isolate->Throw(*error);
-    return Handle<Object>();
+    return isolate->Throw<Object>(error);
   }
 
   Handle<SeededNumberDictionary> new_element_dictionary;
   if (!object->elements()->IsDictionary()) {
     int length = object->IsJSArray()
         ? Smi::cast(Handle<JSArray>::cast(object)->length())->value()
         : object->elements()->length();
     if (length > 0) {
       int capacity = 0;
       int used = 0;
@@ skipping 10884 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal