Replace Chrome IPC with Mojo IPC for querying BatteryStatus service

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index c87bf1f94e13ab068c6f750feb01632b152dcde7..c5e5a5230e60bc66bc7dc575ebccb9a0b65629ec 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -40,7 +40,6 @@
 #include "cc/base/switches.h"
 #include "content/browser/appcache/appcache_dispatcher_host.h"
 #include "content/browser/appcache/chrome_appcache_service.h"
-#include "content/browser/battery_status/battery_status_message_filter.h"
 #include "content/browser/browser_child_process_host_impl.h"
 #include "content/browser/browser_main.h"
 #include "content/browser/browser_main_loop.h"
@@ -132,6 +131,7 @@
 #include "content/public/common/result_codes.h"
 #include "content/public/common/sandboxed_process_launcher_delegate.h"
 #include "content/public/common/url_constants.h"
+#include "device/battery/battery_monitor_impl.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
 #include "ipc/ipc_channel.h"
 #include "ipc/ipc_logging.h"
@@ -438,7 +438,6 @@ RenderProcessHostImpl::RenderProcessHostImpl(
 #endif
       pending_views_(0),
       mojo_application_host_(new MojoApplicationHost),
-      mojo_activation_required_(false),
       visible_widgets_(0),
       backgrounded_(true),
       is_initialized_(false),
@@ -586,6 +585,7 @@ bool RenderProcessHostImpl::Init() {
   GetContentClient()->browser()->RenderProcessWillLaunch(this);
 
   CreateMessageFilters();
+  RegisterMojoServices();
 
   if (run_renderer_in_process()) {
     DCHECK(g_renderer_main_thread_factory);
@@ -643,20 +643,6 @@ bool RenderProcessHostImpl::Init() {
   return true;
 }
 
-void RenderProcessHostImpl::MaybeActivateMojo() {
-  // TODO(darin): Following security review, we can unconditionally initialize
-  // Mojo in all renderers. We will then be able to directly call Activate()
-  // from OnProcessLaunched.
-  if (!mojo_activation_required_)
-    return;  // Waiting on someone to require Mojo.
-
-  if (!GetHandle())
-    return;  // Waiting on renderer startup.
-
-  if (!mojo_application_host_->did_activate())
-    mojo_application_host_->Activate(this, GetHandle());
-}
-
 bool RenderProcessHostImpl::ShouldUseMojoChannel() const {
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
@@ -880,17 +866,20 @@ void RenderProcessHostImpl::CreateMessageFilters() {
   AddFilter(new VibrationMessageFilter());
   AddFilter(new PushMessagingMessageFilter(
       GetID(), storage_partition_impl_->GetServiceWorkerContext()));
-  AddFilter(new BatteryStatusMessageFilter());
 #if defined(OS_ANDROID)
   AddFilter(new ScreenOrientationMessageFilterAndroid());
 #endif
 }
 
+void RenderProcessHostImpl::RegisterMojoServices() {
+  mojo_application_host_->service_registry()->AddService(
+      base::Bind(&device::BatteryMonitorImpl::Create));
+}
+
 int RenderProcessHostImpl::GetNextRoutingID() {
   return widget_helper_->GetNextRoutingID();
 }
 
-
 void RenderProcessHostImpl::ResumeDeferredNavigation(
     const GlobalRequestID& request_id) {
   widget_helper_->ResumeDeferredNavigation(request_id);
@@ -1928,7 +1917,6 @@ void RenderProcessHostImpl::ProcessDied(bool already_dead) {
   }
 
   mojo_application_host_.reset(new MojoApplicationHost);
-  mojo_activation_required_ = false;
 
   // It's possible that one of the calls out to the observers might have caused
   // this object to be no longer needed.
@@ -2095,7 +2083,7 @@ void RenderProcessHostImpl::OnProcessLaunched() {
   // Allow Mojo to be setup before the renderer sees any Chrome IPC messages.
   // This way, Mojo can be safely used from the renderer in response to any
   // Chrome IPC message.
-  MaybeActivateMojo();
+  mojo_application_host_->Activate(this, GetHandle());
 
   while (!queued_messages_.empty()) {
     Send(queued_messages_.front());
@@ -2236,9 +2224,4 @@ void RenderProcessHostImpl::DecrementWorkerRefCount() {
     Cleanup();
 }
 
-void RenderProcessHostImpl::EnsureMojoActivated() {
-  mojo_activation_required_ = true;
-  MaybeActivateMojo();
-}
-
 }  // namespace content