Introduce WebWorkerPermissionClientProxy to deprecate WorkerAllowMainThreadBridge

public/web/WebSharedWorkerClient.h

Index: public/web/WebSharedWorkerClient.h
diff --git a/public/web/WebSharedWorkerClient.h b/public/web/WebSharedWorkerClient.h
index d2c8a2aadfaad858f6ba2cd9ad60c6bf3a76bb6f..3847e269ed526f12b13a87a4d069621d0afaeb5c 100644
--- a/public/web/WebSharedWorkerClient.h
+++ b/public/web/WebSharedWorkerClient.h
@@ -37,8 +37,10 @@
 namespace WebKit {
 
 class WebNotificationPresenter;
+class WebSecurityOrigin;
 class WebString;
 class WebWorker;
+class WebWorkerPermissionClientProxy;
 
 // Provides an interface back to the in-page script object for a worker.
 // All functions are expected to be called back on the thread that created
@@ -54,6 +56,7 @@ public:
 
     // Called on the main webkit thread in the worker process during initialization.
     virtual WebApplicationCacheHost* createApplicationCacheHost(WebApplicationCacheHostClient*) = 0;
+    virtual WebWorkerPermissionClientProxy* createWorkerPermissionClientProxy(const WebSecurityOrigin&) { return 0; }
 
     virtual void dispatchDevToolsMessage(const WebString&) { }
     virtual void saveDevToolsAgentState(const WebString&) { }