ui/gfx/frame_time.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_GFX_FRAME_TIME_H
   6 #define UI_GFX_FRAME_TIME_H
   7
   8 #include "base/time/time.h"
   9 #include "base/logging.h"
  10
  11 namespace gfx {
  12
  13 // FrameTime::Now() should be used to get timestamps with a timebase that
  14 // is consistent across the graphics stack.
  15 class FrameTime {
  16  public:
  17   static base::TimeTicks Now() {
  18     if (TimestampsAreHighRes())
  19       return base::TimeTicks::HighResNow();
  20     return base::TimeTicks::Now();
  21   }
  22
  23 #if defined(OS_WIN)
  24   static base::TimeTicks FromQPCValue(LONGLONG qpc_value) {
  25     DCHECK(TimestampsAreHighRes());
  26     return base::TimeTicks::FromQPCValue(qpc_value);
  27   }
  28 #endif
  29
  30   static bool TimestampsAreHighRes() {
  31     // This should really return base::TimeTicks::IsHighResNowFastAndReliable();
  32     // Returning false makes sure we are only using low-res timestamps until we
  33     // use FrameTime everywhere we need to. See crbug.com/315334
  34     return false;
  35   }
  36 };
  37
  38 }
  39
  40 #endif // UI_GFX_FRAME_TIME_H