Remove GC prolog and epilog

sky/engine/core/script/dart_controller.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sky/engine/core/script/dart_controller.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 113 matching lines @@
 void DartController::CreateIsolateFor(PassOwnPtr<DOMDartState> state) {
   CHECK(kDartIsolateSnapshotBuffer);
   char* error = nullptr;
   dom_dart_state_ = state;
   Dart_Isolate isolate = Dart_CreateIsolate(
       dom_dart_state_->url().utf8().data(), "main", kDartIsolateSnapshotBuffer,
       nullptr, static_cast<DartState*>(dom_dart_state_.get()), &error);
   Dart_SetMessageNotifyCallback(MessageNotifyCallback);
   CHECK(isolate) << error;
   dom_dart_state_->SetIsolate(isolate);
-  Dart_SetGcCallbacks(DartGCPrologue, DartGCEpilogue);
   CHECK(!LogIfError(Dart_SetLibraryTagHandler(DartLibraryTagHandler)));
 
   {
     DartApiScope apiScope;
 
     Builtin::SetNativeResolver(Builtin::kBuiltinLibrary);
     Builtin::SetNativeResolver(Builtin::kMojoInternalLibrary);
     Builtin::SetNativeResolver(Builtin::kIOLibrary);
     BuiltinNatives::Init(BuiltinNatives::MainIsolate);
 
     builtin_sky_ = adoptPtr(new BuiltinSky(dart_state()));
     dart_state()->class_library().set_provider(builtin_sky_.get());
 
     if (dart_state()->document())
       builtin_sky_->InstallWindow(dart_state());
 
     EnsureHandleWatcherStarted();
   }
   Dart_ExitIsolate();
 }
 
 void DartController::InstallView(View* view) {
   DartIsolateScope isolate_scope(dart_state()->isolate());
   DartApiScope dart_api_scope;
 
   builtin_sky_->InstallView(view);
 }
 
 } // namespace blink