gfx: Add FrameTime and DisplayTime classes

cc/layers/heads_up_display_layer_impl.cc

 // Copyright 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 "cc/layers/heads_up_display_layer_impl.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/strings/stringprintf.h"
@@ skipping 170 matching lines @@
 }
 
 void HeadsUpDisplayLayerImpl::DidLoseOutputSurface() { hud_resource_.reset(); }
 
 bool HeadsUpDisplayLayerImpl::LayerIsAlwaysDamaged() const { return true; }
 
 void HeadsUpDisplayLayerImpl::UpdateHudContents() {
   const LayerTreeDebugState& debug_state = layer_tree_impl()->debug_state();
 
   // Don't update numbers every frame so text is readable.
-  base::TimeTicks now = layer_tree_impl()->CurrentFrameTimeTicks();
-  if (base::TimeDelta(now - time_of_last_graph_update_).InSecondsF() > 0.25f) {
-    time_of_last_graph_update_ = now;
+  gfx::FrameTime frame_time = layer_tree_impl()->CurrentFrameTimeTicks();
+  if ((frame_time - time_of_last_graph_update_).InSecondsF() > 0.25f) {
+    time_of_last_graph_update_ = frame_time;
 
     if (debug_state.show_fps_counter) {
       FrameRateCounter* fps_counter = layer_tree_impl()->frame_rate_counter();
       fps_graph_.value = fps_counter->GetAverageFPS();
       fps_counter->GetMinAndMaxFPS(&fps_graph_.min, &fps_graph_.max);
     }
 
     if (debug_state.continuous_painting) {
       PaintTimeCounter* paint_time_counter =
           layer_tree_impl()->paint_time_counter();
@@ skipping 493 matching lines @@
       canvas->restore();
     }
   }
 }
 
 const char* HeadsUpDisplayLayerImpl::LayerTypeAsString() const {
   return "cc::HeadsUpDisplayLayerImpl";
 }
 
 }  // namespace cc