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 2ef10a481ddebc38d8dd04dd3127f911a0285bdd..743cd1312e70f7dc392a852e5aa7061b203dfa4a 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -11,6 +11,8 @@
 #include "base/basictypes.h"
 #include "base/cancelable_callback.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/power_monitor/power_monitor.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"
@@ -33,6 +35,7 @@ namespace cc {
 class SchedulerClient {
  public:
   virtual BeginFrameSource* ExternalBeginFrameSource() = 0;
+  virtual base::PowerMonitor* PowerMonitor() = 0;
   virtual void WillBeginImplFrame(const BeginFrameArgs& args) = 0;
   virtual void ScheduledActionSendBeginMainFrame() = 0;
   virtual DrawResult ScheduledActionDrawAndSwapIfPossible() = 0;
@@ -71,7 +74,8 @@ class CC_EXPORT SchedulerFrameSourcesConstructor {
   friend class Scheduler;
 };
 
-class CC_EXPORT Scheduler : public BeginFrameObserverMixIn {
+class CC_EXPORT Scheduler : public BeginFrameObserverMixIn,
+                            public base::PowerObserver {
  public:
   static scoped_ptr<Scheduler> Create(
       SchedulerClient* client,
@@ -88,6 +92,9 @@ class CC_EXPORT Scheduler : public BeginFrameObserverMixIn {
 
   virtual ~Scheduler();
 
+  // base::PowerObserver method.
+  virtual void OnPowerStateChange(bool on_battery_power) override;
+
   const SchedulerSettings& settings() const { return settings_; }
 
   void CommitVSyncParameters(base::TimeTicks timebase,
@@ -223,6 +230,8 @@ class CC_EXPORT Scheduler : public BeginFrameObserverMixIn {
   void OnBeginImplFrameDeadline();
   void PollForAnticipatedDrawTriggers();
   void PollToAdvanceCommitState();
+  void SetupPowerMonitoring();
+  void TeardownPowerMonitoring();
 
   base::TimeDelta EstimatedParentDrawTime() {
     return estimated_parent_draw_time_;