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

Source/core/workers/WorkerV8Isolate.h

Index: Source/core/workers/WorkerV8Isolate.h
diff --git a/Source/core/workers/WorkerV8Isolate.h b/Source/core/workers/WorkerV8Isolate.h
new file mode 100644
index 0000000000000000000000000000000000000000..fee18955195bdf3a40e6cbc0ed08bdb8199748b7
--- /dev/null
+++ b/Source/core/workers/WorkerV8Isolate.h
@@ -0,0 +1,30 @@
+// 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 {
+
+class CORE_EXPORT WorkerV8Isolate {

[kinuko, 2015/05/28 16:21:59]

nit: please add class-level comment

[sadrul, 2015/05/28 16:51:56]

Done.

+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