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

Source/core/workers/WorkerV8Isolate.cpp

Index: Source/core/workers/WorkerV8Isolate.cpp
diff --git a/Source/core/workers/WorkerV8Isolate.cpp b/Source/core/workers/WorkerV8Isolate.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..fdcaf4a2bbbc954c56b47b967c93f96c66e3f107
--- /dev/null
+++ b/Source/core/workers/WorkerV8Isolate.cpp
@@ -0,0 +1,60 @@
+// 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 "config.h"
+#include "core/workers/WorkerV8Isolate.h"
+
+#include "bindings/core/v8/V8Binding.h"
+#include "bindings/core/v8/V8GCController.h"
+#include "bindings/core/v8/V8Initializer.h"
+#include "bindings/core/v8/V8PerIsolateData.h"
+
+namespace blink {
+
+namespace {
+
+class WorkerV8IsolateDefault final : public WorkerV8Isolate {
+    WTF_MAKE_NONCOPYABLE(WorkerV8IsolateDefault);
+public:
+    WorkerV8IsolateDefault()
+        : m_isolate(V8PerIsolateData::initialize())
+    {
+        V8Initializer::initializeWorker(m_isolate);
+
+        m_interruptor = adoptPtr(new V8IsolateInterruptor(m_isolate));
+        ThreadState::current()->addInterruptor(m_interruptor.get());
+        ThreadState::current()->registerTraceDOMWrappers(m_isolate, V8GCController::traceDOMWrappers);
+    }
+
+    ~WorkerV8IsolateDefault() override
+    {
+        V8PerIsolateData::destroy(m_isolate);
+    }
+
+    v8::Isolate* isolate() const override { return m_isolate; }
+    void willDestroy() override
+    {
+        ASSERT(m_isolate);
+        V8PerIsolateData::willBeDestroyed(m_isolate);
+        ThreadState::current()->removeInterruptor(m_interruptor.get());
+    }
+
+    void terminateExecution() override
+    {
+        v8::V8::TerminateExecution(m_isolate);
+    }
+
+private:
+    v8::Isolate* m_isolate;
+    OwnPtr<V8IsolateInterruptor> m_interruptor;
+};
+
+} // namespace
+
+PassOwnPtr<WorkerV8Isolate> WorkerV8Isolate::createDefault()
+{
+    return adoptPtr(new WorkerV8IsolateDefault());
+}
+
+} // namespace blink