Support UseCounter in dedicated workers.

Source/core/workers/WorkerObjectProxy.h

Index: Source/core/workers/WorkerObjectProxy.h
diff --git a/Source/core/workers/WorkerObjectProxy.h b/Source/core/workers/WorkerObjectProxy.h
index cf055e15c2574c34c7218af2429fcdad7765914c..7d20a91edc254fe100e81259963b53f871c38bf8 100644
--- a/Source/core/workers/WorkerObjectProxy.h
+++ b/Source/core/workers/WorkerObjectProxy.h
@@ -39,6 +39,7 @@
 namespace WebCore {
 
 class ExecutionContext;
+class ExecutionContextTask;
 class WorkerMessagingProxy;
 
 // A proxy to talk to the worker object. This object is created on the
@@ -53,7 +54,7 @@ public:
     virtual ~WorkerObjectProxy() { }
 
     void postMessageToWorkerObject(PassRefPtr<SerializedScriptValue>, PassOwnPtr<MessagePortChannelArray>);
-
+    void postTaskToMainExecutionContext(PassOwnPtr<ExecutionContextTask>);
     void confirmMessageFromWorkerObject(bool hasPendingActivity);
     void reportPendingActivity(bool hasPendingActivity);