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

third_party/WebKit/public/platform/ServiceRegistry.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ServiceRegistry_h
+#define ServiceRegistry_h
+
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "mojo/public/cpp/system/message_pipe.h"
+#include "public/platform/WebCommon.h"
+
+namespace blink {
+
+class BLINK_PLATFORM_EXPORT ServiceRegistry {
+public:
+    virtual void connectToRemoteService(const char* name, mojo::ScopedMessagePipeHandle) = 0;
+
+    template <typename Interface>
+    void connectToRemoteService(mojo::InterfaceRequest<Interface> ptr)
+    {
+        connectToRemoteService(Interface::Name_, ptr.PassMessagePipe());
+    }
+
+    static ServiceRegistry* getEmptyServiceRegistry();
+};
+
+} // namespace blink
+
+#endif