Enable high resolution time for TimeTicks::Now on Windows Canary

base/threading/platform_thread_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/threading/platform_thread.h"
 
 #include "base/debug/alias.h"
 #include "base/debug/profiler.h"
 #include "base/logging.h"
 #include "base/threading/thread_id_name_manager.h"
@@ skipping 117 matching lines @@
   return PlatformThreadHandle();
 }
 
 // static
 void PlatformThread::YieldCurrentThread() {
   ::Sleep(0);
 }
 
 // static
 void PlatformThread::Sleep(TimeDelta duration) {
-  ::Sleep(duration.InMillisecondsRoundedUp());
+  // When measured with a high resolution clock, Sleep() sometimes returns much
+  // too early. We may need to call it repeatedly to get the desired duration.
+  TimeTicks end = TimeTicks::Now() + duration;
+  TimeTicks now;
+  while ((now = TimeTicks::Now()) < end)
+    ::Sleep((end - now).InMillisecondsRoundedUp());
 }
 
 // static
 void PlatformThread::SetName(const char* name) {
   ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
 
   // On Windows only, we don't need to tell the profiler about the "BrokerEvent"
   // thread, as it exists only in the chrome.exe image, and never spawns or runs
   // tasks (items which could be profiled).  This test avoids the notification,
   // which would also (as a side effect) initialize the profiler in this unused
@@ skipping 76 matching lines @@
     case kThreadPriority_RealtimeAudio:
       ::SetThreadPriority(handle.handle_, THREAD_PRIORITY_TIME_CRITICAL);
       break;
     default:
       NOTREACHED() << "Unknown priority.";
       break;
   }
 }
 
 }  // namespace base