Implement initial part of WebEmbeddedWorker

public/web/WebServiceWorkerContextProxy.h

Index: public/web/WebServiceWorkerContextProxy.h
diff --git a/public/web/WebServiceWorkerContextProxy.h b/public/web/WebServiceWorkerContextProxy.h
index d011778335492029d5faa6375a75cec86996d509..99cc9b74f02b2723e7c7e52d77a5ba25c249c4c7 100644
--- a/public/web/WebServiceWorkerContextProxy.h
+++ b/public/web/WebServiceWorkerContextProxy.h
@@ -37,6 +37,8 @@ namespace blink {
 // All methods of this class must be called on the worker thread.
 class WebServiceWorkerContextProxy {
 public:
+    virtual ~WebServiceWorkerContextProxy() { }
+
     // FIXME: Add service-worker specific methods.
 
     virtual void resumeWorkerContext() { }