Remove LifecycleNotifier<>::m_context.

Source/core/dom/ExecutionContext.h

Index: Source/core/dom/ExecutionContext.h
diff --git a/Source/core/dom/ExecutionContext.h b/Source/core/dom/ExecutionContext.h
index 99a5a1a9209a0ae2b18a927c7f53784a23d8129f..10f6409b55f55256cd31baf8bf2c935f9c176243 100644
--- a/Source/core/dom/ExecutionContext.h
+++ b/Source/core/dom/ExecutionContext.h
@@ -63,6 +63,9 @@ public:
     virtual bool isSharedWorkerGlobalScope() const { return false; }
     virtual bool isServiceWorkerGlobalScope() const { return false; }
     virtual bool isJSExecutionForbidden() const { return false; }
+
+    virtual bool isContextThread() const { return true; }
+
     SecurityOrigin* securityOrigin();
     ContentSecurityPolicy* contentSecurityPolicy();
     const KURL& url() const;