High resolution timer fix reland

base/message_loop/message_loop.h

Index: base/message_loop/message_loop.h
diff --git a/base/message_loop/message_loop.h b/base/message_loop/message_loop.h
index 39a1b686bac46b698b04c26585ce1e3d23def8ea..8db1e77daf38b21e191df7c0108b6abe0d6571fe 100644
--- a/base/message_loop/message_loop.h
+++ b/base/message_loop/message_loop.h
@@ -371,10 +371,6 @@ class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
   void AddTaskObserver(TaskObserver* task_observer);
   void RemoveTaskObserver(TaskObserver* task_observer);
 
-  // When we go into high resolution timer mode, we will stay in hi-res mode
-  // for at least 1s.
-  static const int kHighResolutionTimerModeLeaseTimeMs = 1000;
-
 #if defined(OS_WIN)
   void set_os_modal_loop(bool os_modal_loop) {
     os_modal_loop_ = os_modal_loop;
@@ -390,7 +386,7 @@ class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
 
   // Returns true if the message loop has high resolution timers enabled.
   // Provided for testing.
-  bool IsHighResolutionTimerEnabledForTesting();
+  bool HasHighResolutionTasks();
 
   // Returns true if the message loop is "idle". Provided for testing.
   bool IsIdleForTesting();
@@ -459,6 +455,14 @@ class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
   // this queue is only accessed (push/pop) by our current thread.
   TaskQueue work_queue_;
 
+  // How many high resolution tasks are in the pending task queue. This value
+  // increases by N every time we call ReloadWorkQueue() and decreases by 1
+  // every time we call RunTask() if the task needs a high resolution timer.
+  int pending_high_res_tasks_;
+  // Tracks if we have requested high resolution timers. Its only use is to
+  // turn off the high resolution timer upon loop destruction.
+  bool in_high_res_mode_;
+
   // Contains delayed tasks, sorted by their 'delayed_run_time' property.
   DelayedTaskQueue delayed_work_queue_;