chromeos: Add support for the battery status API on chromeos.

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 19e02596992b6b79122616234bda21a0afe0ba02..62314e5410ecfab5308ad27ed1af9dc85a05cf8f 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -46,6 +46,7 @@
 #include "content/public/renderer/content_renderer_client.h"
 #include "content/public/renderer/render_process_observer.h"
 #include "content/public/renderer/render_view_visitor.h"
+#include "content/renderer/battery_status_dispatcher.h"
 #include "content/renderer/browser_plugin/old/browser_plugin_channel_manager.h"
 #include "content/renderer/browser_plugin/old/browser_plugin_registry.h"
 #include "content/renderer/devtools_agent_filter.h"
@@ -69,6 +70,7 @@
 #include "media/base/media.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebBatteryMonitor.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebColorName.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCompositor.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDatabase.h"
@@ -1000,6 +1002,18 @@ GpuChannelHost* RenderThreadImpl::GetGpuChannel() {
   return gpu_channel_.get();
 }
 
+WebKit::WebBatteryMonitor* RenderThreadImpl::GetBatteryMonitor() {
+#if defined(OS_CHROMEOS)
+  if (!battery_monitor_.get()) {
+    content::BatteryStatusDispatcher* dispatcher =
+        new content::BatteryStatusDispatcher;
+    battery_monitor_.reset(dispatcher);
+    AddObserver(dispatcher);
+  }
+#endif
+  return battery_monitor_.get();
+}
+
 void RenderThreadImpl::OnPurgePluginListCache(bool reload_pages) {
   EnsureWebKitInitialized();
   // The call below will cause a GetPlugins call with refresh=true, but at this