compositor-worker: Share a thread and an isolate for compositor workers.

Source/core/workers/WorkerV8Isolate.h

+// 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.
+
+#ifndef WorkerV8Isolate_h
+#define WorkerV8Isolate_h
+
+#include "core/CoreExport.h"
+#include "wtf/OwnPtr.h"
+#include "wtf/PassOwnPtr.h"
+#include <v8.h>
+
+namespace blink {
+
+// A common interface for a worker to manage the v8::Isolate used for the worker.

[kinuko, 2015/05/31 15:18:24]

Please also note about its lifetime (when it's created and when it's destroyed)
and also that it doesn't necessarily tied to a single v8::Isolate.

[sadrul, 2015/06/01 05:24:11]

Done.

+class CORE_EXPORT WorkerV8Isolate {
+public:
+    static PassOwnPtr<WorkerV8Isolate> createDefault();
+    virtual ~WorkerV8Isolate() { }
+
+    virtual v8::Isolate* isolate() const = 0;
+    virtual void willDestroy() = 0;
+    virtual void terminateExecution() = 0;
+
+protected:
+    WorkerV8Isolate() { }
+};
+
+} // namespace blink
+
+#endif // WorkerV8Isolate_h