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

Source/core/workers/DedicatedWorkerThread.cpp

Index: Source/core/workers/DedicatedWorkerThread.cpp
diff --git a/Source/core/workers/DedicatedWorkerThread.cpp b/Source/core/workers/DedicatedWorkerThread.cpp
index 1567ddae3959d8e776c248f24f642644a0ffae52..385d25951c150942ea3d0e4eb3c9e0b99dddd4b0 100644
--- a/Source/core/workers/DedicatedWorkerThread.cpp
+++ b/Source/core/workers/DedicatedWorkerThread.cpp
@@ -66,6 +66,11 @@ WebThreadSupportingGC& DedicatedWorkerThread::backingThread()
     return *m_thread.get();
 }
 
+PassOwnPtr<WorkerIsolateWrapper> DedicatedWorkerThread::createIsolateWrapper()
+{
+    return WorkerIsolateWrapper::createDefault();

[kinuko, 2015/06/01 13:15:41]

I'm fine moving this to WorkerThread's default impl.

[sadrul, 2015/06/01 14:21:16]

Done.

+}
+
 void DedicatedWorkerThread::postInitialize()
 {
     // Notify the parent object of our current active state before the event