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

third_party/WebKit/Source/platform/exported/ServiceRegistry.cpp

+// 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.
+
+#include "public/platform/ServiceRegistry.h"
+
+#include "wtf/StdLibExtras.h"
+
+namespace blink {
+namespace {
+
+class EmptyServiceRegistry : public ServiceRegistry {
+    void connectToRemoteService(const char* name, mojo::ScopedMessagePipeHandle) override {}
+};
+
+}
+
+ServiceRegistry* ServiceRegistry::getEmptyServiceRegistry()
+{
+    DEFINE_STATIC_LOCAL(EmptyServiceRegistry, emptyServiceRegistry, ());
+    return &emptyServiceRegistry;
+}
+
+}