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

content/renderer/mojo/blink_service_registry_wrapper.cc

+// 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 "content/renderer/mojo/blink_service_registry_wrapper.h"
+
+#include <utility>
+
+#include "base/strings/string_piece.h"
+#include "content/common/mojo/service_registry_impl.h"
+#include "content/renderer/render_thread_impl.h"
+#include "device/battery/battery_monitor.mojom.h"

[esprehn, 2016/03/29 05:26:20]

this is a really bad layering violation that the core content/ service registry
knows about battery_monitor.

+
+namespace content {
+
+BlinkServiceRegistryWrapper::BlinkServiceRegistryWrapper(
+    content::ServiceRegistry* service_registry)
+    : service_registry_(
+          static_cast<ServiceRegistryImpl*>(service_registry)->GetWeakPtr()) {}
+
+BlinkServiceRegistryWrapper::~BlinkServiceRegistryWrapper() = default;
+
+void BlinkServiceRegistryWrapper::connectToRemoteService(
+    const char* name,
+    mojo::ScopedMessagePipeHandle handle) {
+  if (!service_registry_)
+    return;
+
+  // In the layout test mode, mock services should be used instead.
+  // TODO(yukishiino): We'd like to inject mock services implemented in
+  // JavaScript.  Remove the following hack once we support JS-bindings
+  // of Mojo and service mocking in JS.
+  if (RenderThreadImpl::current() &&
+      RenderThreadImpl::current()->layout_test_mode() &&
+      base::StringPiece(name) == device::BatteryMonitor::Name_) {

[esprehn, 2016/03/29 05:26:20]

woah, this is a crazy hack. We really should fix this asap. Also this used to be
guarded with !OS(ANDROID) but you removed it. Is that right?

[Sam McNally, 2016/03/30 00:20:53]

I'm going to change battery status to avoid this:
https://codereview.chromium.org/1836203002/.

+    return;
+  }
+
+  service_registry_->ConnectToRemoteService(name, std::move(handle));
+}
+
+}  // namespace content