Remove more uses of Isolate::current_zone.

runtime/vm/handles_impl.h

 // 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.
 
 #ifndef VM_HANDLES_IMPL_H_
 #define VM_HANDLES_IMPL_H_
 
 #include "vm/heap.h"
 #include "vm/thread.h"
 #include "vm/visitor.h"
@@ skipping 105 matching lines @@
   ASSERT(thread->zone() == zone);
   ASSERT(thread->no_handle_scope_depth() == 0);
 #endif  // DEBUG
   Handles* handles = zone->handles();
   ASSERT(handles != NULL);
   uword address = handles->AllocateHandleInZone();
   return address;
 }
 
 
-// Figure out the current zone using the current Isolate and
+// Figure out the current zone using the current Thread and
 // check if the specified handle has been allocated in this zone.
 template <int kHandleSizeInWords, int kHandlesPerChunk, int kOffsetOfRawPtr>
 bool Handles<kHandleSizeInWords,
              kHandlesPerChunk,
              kOffsetOfRawPtr>::IsZoneHandle(uword handle) {
-  // TODO(5411412): Accessing the current isolate is a performance problem,
+  // TODO(5411412): Accessing the current thread is a performance problem,
   // consider passing it down as a parameter.
-  Isolate* isolate = Isolate::Current();
-  ASSERT(isolate != NULL);
-  ASSERT(isolate->current_zone() != NULL);
-  Handles* handles = isolate->current_zone()->handles();
+  Thread* thread = Thread::Current();
+  ASSERT(thread != NULL);
+  ASSERT(thread->zone() != NULL);
+  Handles* handles = thread->zone()->handles();
   ASSERT(handles != NULL);
   return handles->IsValidZoneHandle(handle);
 }
 
 
 template <int kHandleSizeInWords, int kHandlesPerChunk, int kOffsetOfRawPtr>
 void Handles<kHandleSizeInWords,
              kHandlesPerChunk,
              kOffsetOfRawPtr>::DeleteAll() {
   // Delete all the zone allocated handle blocks.
@@ skipping 221 matching lines @@
 template <int kHandleSizeInWords, int kHandlesPerChunk, int kOffsetOfRawPtr>
 int Handles<kHandleSizeInWords,
             kHandlesPerChunk,
             kOffsetOfRawPtr>::HandlesBlock::HandleCount() const {
   return (next_handle_slot_ / kHandleSizeInWords);
 }
 
 }  // namespace dart
 
 #endif  // VM_HANDLES_IMPL_H_