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

content/renderer/mojo/blink_service_registry_impl.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 CONTENT_RENDERER_MOJO_BLINK_SERVICE_REGISTRY_IMPL_H_
+#define CONTENT_RENDERER_MOJO_BLINK_SERVICE_REGISTRY_IMPL_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "mojo/public/cpp/system/message_pipe.h"
+#include "third_party/WebKit/public/platform/ServiceRegistry.h"
+
+namespace content {
+
+class ServiceRegistry;
+
+// An implementation of blink::ServiceRegistry that forwards to a
+// content::ServiceRegistry.
+class BlinkServiceRegistryImpl : public blink::ServiceRegistry {
+ public:
+  explicit BlinkServiceRegistryImpl(
+      base::WeakPtr<content::ServiceRegistry> service_registry);
+  ~BlinkServiceRegistryImpl();
+
+  // blink::ServiceRegistry override.
+  void connectToRemoteService(const char* name,
+                              mojo::ScopedMessagePipeHandle handle) override;
+
+ private:
+  const base::WeakPtr<content::ServiceRegistry> service_registry_;
+
+  DISALLOW_COPY_AND_ASSIGN(BlinkServiceRegistryImpl);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MOJO_BLINK_SERVICE_REGISTRY_IMPL_H_