[Device Service] Move PowerMonitor into the Device Service

content/child/child_thread_impl.cc

Index: content/child/child_thread_impl.cc
diff --git a/content/child/child_thread_impl.cc b/content/child/child_thread_impl.cc
index a92624a1e45009ec55dd987fe5406cbac5eaec29..d1a5e11ae6c095b88f4a7cd4068be046126c6c91 100644
--- a/content/child/child_thread_impl.cc
+++ b/content/child/child_thread_impl.cc
@@ -67,6 +67,7 @@
 #include "mojo/edk/embedder/scoped_ipc_support.h"
 #include "mojo/public/cpp/system/buffer.h"
 #include "mojo/public/cpp/system/platform_handle.h"
+#include "services/device/public/cpp/constants.h"
 #include "services/service_manager/public/cpp/connector.h"
 #include "services/service_manager/public/cpp/interface_factory.h"
 #include "services/service_manager/public/cpp/interface_provider.h"
@@ -538,10 +539,17 @@ void ChildThreadImpl::Init(const Options& options) {
     channel_->AddFilter(new ChildMemoryMessageFilter());
   }
 
-  // In single process mode we may already have a power monitor
+  // In single process mode we may already have a power monitor.
   if (!base::PowerMonitor::Get()) {
+    std::unique_ptr<service_manager::Connection> device_connection;
+    service_manager::InterfaceProvider* remote_interfaces = nullptr;
+    if (service_manager_connection_) {

[leonhsl(Using Gerrit), 2016/11/17 10:28:03]

Should we use DCHECK(service_manager_connection_) here? I'm not sure whether
child processes are all acting as service or not.

[blundell, 2016/11/22 16:46:44]

I'm not sure either. Ken?

[Ken Rockot(use gerrit already), 2016/11/22 17:23:40]

There are still a few edge cases where there is no ServiceManagerConnection, so
no, it's not OK to DCHECK here. As a nit though, I would just do

  if (!base::PowerMonitor::Get() && service_manager_connection_) { 
     // ...

+      device_connection = service_manager_connection_->GetConnector()->Connect(
+          device::kDeviceServiceName);
+      remote_interfaces = device_connection->GetRemoteInterfaces();
+    }
     std::unique_ptr<device::PowerMonitorBroadcastSource> power_monitor_source(
-        new device::PowerMonitorBroadcastSource(GetRemoteInterfaces()));
+        new device::PowerMonitorBroadcastSource(remote_interfaces));
 
     power_monitor_.reset(
         new base::PowerMonitor(std::move(power_monitor_source)));