Move CHA state keeping from Isolate to Thread.

runtime/vm/cha.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/cha.h"
 #include "vm/class_table.h"
 #include "vm/flags.h"
 #include "vm/freelist.h"
 #include "vm/object.h"
 #include "vm/raw_object.h"
 #include "vm/visitor.h"
 
 namespace dart {
 
 void CHA::AddToLeafClasses(const Class& cls) {
   for (intptr_t i = 0; i < leaf_classes_.length(); i++) {
     if (leaf_classes_[i]->raw() == cls.raw()) {
       return;
     }
   }
-  leaf_classes_.Add(&Class::ZoneHandle(isolate_, cls.raw()));
+  leaf_classes_.Add(&Class::ZoneHandle(thread_->zone(), cls.raw()));
 }
 
 
 bool CHA::HasSubclasses(const Class& cls) {
   ASSERT(!cls.IsNull());
   ASSERT(cls.id() >= kInstanceCid);
   // Can't track dependencies for classes on the VM heap since those are
   // read-only.
   // TODO(fschneider): Enable tracking of CHA dependent code for VM heap
   // classes.
   if (cls.InVMHeap()) return true;
 
   if (cls.IsObjectClass()) {
     // Class Object has subclasses, although we do not keep track of them.
     return true;
   }
   const GrowableObjectArray& direct_subclasses =
-      GrowableObjectArray::Handle(isolate_, cls.direct_subclasses());
+      GrowableObjectArray::Handle(thread_->zone(), cls.direct_subclasses());
   bool result =
       !direct_subclasses.IsNull() && (direct_subclasses.Length() > 0);
   if (!result) {
     AddToLeafClasses(cls);
   }
   return result;
 }
 
 
 bool CHA::HasSubclasses(intptr_t cid) {
-  const ClassTable& class_table = *isolate_->class_table();
-  Class& cls = Class::Handle(isolate_, class_table.At(cid));
+  const ClassTable& class_table = *thread_->isolate()->class_table();
+  Class& cls = Class::Handle(thread_->zone(), class_table.At(cid));
   return HasSubclasses(cls);
 }
 
 
 bool CHA::IsImplemented(const Class& cls) {
   // Signature classes have different type checking rules.
   ASSERT(!cls.IsSignatureClass());
   // Can't track dependencies for classes on the VM heap since those are
   // read-only.
   // TODO(fschneider): Enable tracking of CHA dependent code for VM heap
   // classes.
   if (cls.InVMHeap()) return true;
 
   bool result = cls.is_implemented();
   if (!result) {
     AddToLeafClasses(cls);
   }
   return result;
 }
 
 
 bool CHA::HasOverride(const Class& cls, const String& function_name) {
   const GrowableObjectArray& cls_direct_subclasses =
-      GrowableObjectArray::Handle(isolate_, cls.direct_subclasses());
+      GrowableObjectArray::Handle(thread_->zone(), cls.direct_subclasses());
   // Subclasses of Object are not tracked by CHA. Safely assume that overrides
   // exist.
   if (cls.IsObjectClass()) {
     return true;
   }
 
   if (cls_direct_subclasses.IsNull()) {
     AddToLeafClasses(cls);
     return false;
   }
-  Class& direct_subclass = Class::Handle(isolate_);
+  Class& direct_subclass = Class::Handle(thread_->zone());
   for (intptr_t i = 0; i < cls_direct_subclasses.Length(); i++) {
     direct_subclass ^= cls_direct_subclasses.At(i);
     // Unfinalized classes are treated as non-existent for CHA purposes,
     // as that means that no instance of that class exists at runtime.
     if (direct_subclass.is_finalized() &&
         (direct_subclass.LookupDynamicFunction(function_name) !=
          Function::null())) {
       return true;
     }
     if (HasOverride(direct_subclass, function_name)) {
       return true;
     }
   }
   AddToLeafClasses(cls);
   return false;
 }
 
 }  // namespace dart