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 8ac6ce0ffe602fa3cc5abc74901caac399f82eb4..bb14639fabe8ea89bf50a190242261def7fe44ff 100644
--- a/third_party/WebKit/public/web/WebFrameClient.h
+++ b/third_party/WebKit/public/web/WebFrameClient.h
@@ -59,6 +59,7 @@
 namespace blink {
 
 enum class WebTreeScopeType;
+class ServiceRegistry;
 class WebApplicationCacheHost;
 class WebApplicationCacheHostClient;
 class WebAppBannerClient;
@@ -720,6 +721,9 @@ 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() { }
 };