Implement empty WorkerInternals interface.

third_party/WebKit/public/platform/Platform.h

Index: third_party/WebKit/public/platform/Platform.h
diff --git a/third_party/WebKit/public/platform/Platform.h b/third_party/WebKit/public/platform/Platform.h
index 050f06ceb5ff8316c9ce46ec7d2059356cd69d4b..0dfb06c0e5dbd75cf5c61b31bb99c93e4afa7494 100644
--- a/third_party/WebKit/public/platform/Platform.h
+++ b/third_party/WebKit/public/platform/Platform.h
@@ -57,6 +57,11 @@
 
 class GrContext;
 
+namespace v8 {
+class Context;
+template<class T> class Local;
+}
+
 namespace blink {
 
 class ServiceRegistry;
@@ -533,6 +538,7 @@ public:
 
     virtual void didStartWorkerThread() { }
     virtual void willStopWorkerThread() { }
+    virtual void workerContextCreated(const v8::Local<v8::Context>& worker) { }
 
     // WebCrypto ----------------------------------------------------------