2 files changed, 7 insertions, 2 deletions
diff --git a/base/message_loop/message_loop.cc b/base/message_loop/message_loop.cc
index 16b999c..c01e542 100644
--- a/base/message_loop/message_loop.cc
+++ b/base/message_loop/message_loop.cc
@@ -616,8 +616,11 @@ bool MessageLoop::DoIdleWork() {
   // _if_ triggered by the timer happens with good resolution. If we don't
   // do this the default resolution is 15ms which might not be acceptable
   // for some tasks.
-  in_high_res_mode_ = pending_high_res_tasks_ > 0;
-  Time::ActivateHighResolutionTimer(in_high_res_mode_);
+  bool high_res = pending_high_res_tasks_ > 0;
+  if (high_res != in_high_res_mode_) {
+    in_high_res_mode_ = high_res;
+    Time::ActivateHighResolutionTimer(in_high_res_mode_);
+  }
 #endif
   return false;
 }
diff --git a/base/message_loop/message_loop_unittest.cc b/base/message_loop/message_loop_unittest.cc
index 866c20b..0a6e817 100644
--- a/base/message_loop/message_loop_unittest.cc
+++ b/base/message_loop/message_loop_unittest.cc
@@ -726,6 +726,7 @@ TEST(MessageLoopTest, WaitForIO) {
 
 TEST(MessageLoopTest, HighResolutionTimer) {
   MessageLoop loop;
+  Time::EnableHighResolutionTimer(true);
 
   const TimeDelta kFastTimer = TimeDelta::FromMilliseconds(5);
   const TimeDelta kSlowTimer = TimeDelta::FromMilliseconds(100);
@@ -744,6 +745,7 @@ TEST(MessageLoopTest, HighResolutionTimer) {
   EXPECT_FALSE(loop.HasHighResolutionTasks());
   loop.Run();
   EXPECT_FALSE(loop.HasHighResolutionTasks());
+  Time::EnableHighResolutionTimer(false);
 }
 
 #endif  // defined(OS_WIN)