Disable scheduler deadline task on battery power in Windows

cc/scheduler/scheduler.h

Index: cc/scheduler/scheduler.h
diff --git a/cc/scheduler/scheduler.h b/cc/scheduler/scheduler.h
index 97b17b7283aaf4e357be4fd8e5726298f80c63cf..53d6b8ac569e13101b9136ebd86d415edd092a2b 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -11,6 +11,7 @@
 #include "base/basictypes.h"
 #include "base/cancelable_callback.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/power_monitor/power_observer.h"
 #include "base/time/time.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/begin_frame_args.h"
@@ -51,7 +52,7 @@ class SchedulerClient {
   virtual ~SchedulerClient() {}
 };
 
-class CC_EXPORT Scheduler {
+class CC_EXPORT Scheduler : public base::PowerObserver {
  public:
   static scoped_ptr<Scheduler> Create(
       SchedulerClient* client,
@@ -64,6 +65,9 @@ class CC_EXPORT Scheduler {
 
   virtual ~Scheduler();
 
+  // base::PowerObserver method.
+  virtual void OnPowerStateChange(bool on_battery_power) OVERRIDE;
+
   const SchedulerSettings& settings() const { return settings_; }
 
   void CommitVSyncParameters(base::TimeTicks timebase,
@@ -198,6 +202,8 @@ class CC_EXPORT Scheduler {
   bool inside_process_scheduled_actions_;
   SchedulerStateMachine::Action inside_action_;
 
+  bool on_battery_power_;
+
  private:
   base::TimeTicks AdjustedBeginImplFrameDeadline(
       const BeginFrameArgs& args,
@@ -216,10 +222,13 @@ class CC_EXPORT Scheduler {
   void SetupSyntheticBeginFrames();
   void BeginRetroFrame();
   void BeginUnthrottledFrame();
+  bool ShouldPostBeginImplFrameDeadline();
   void BeginImplFrame(const BeginFrameArgs& args);
   void OnBeginImplFrameDeadline();
   void PollForAnticipatedDrawTriggers();
   void PollToAdvanceCommitState();
+  void SetupPowerMonitoring();
+  void TeardownPowerMonitoring();
 
   base::TimeDelta VSyncInterval() { return vsync_interval_; }