Add blink::ServiceRegistry and expose it from LocalFrame and Platform.

third_party/WebKit/public/web/WebFrameClient.h

Index: third_party/WebKit/public/web/WebFrameClient.h
diff --git a/third_party/WebKit/public/web/WebFrameClient.h b/third_party/WebKit/public/web/WebFrameClient.h
index 5fd21c9dc1ceb855c01633ff06731e3ecf9f89b1..6bb89642ec1d58d5f3b5edf72bbbcebf13cbedaa 100644
--- a/third_party/WebKit/public/web/WebFrameClient.h
+++ b/third_party/WebKit/public/web/WebFrameClient.h
@@ -60,6 +60,7 @@
 namespace blink {
 
 enum class WebTreeScopeType;
+class ServiceRegistry;
 class WebApplicationCacheHost;
 class WebApplicationCacheHostClient;
 class WebAppBannerClient;
@@ -723,6 +724,9 @@ public:
     // This method takes ownership of the callbacks pointer.
     virtual void checkIfAudioSinkExistsAndIsAuthorized(const WebString& sinkId, const WebSecurityOrigin&, WebSetSinkIdCallbacks*) { BLINK_ASSERT_NOT_REACHED(); }
 
+    // Mojo ----------------------------------------------------------------
+    virtual ServiceRegistry* serviceRegistry() { return nullptr; }
+
 protected:
     virtual ~WebFrameClient() { }
 };