Read compositor VSync information from platform, when possible

ash/display/display_change_observer_chromeos.cc

 // Copyright 2013 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 "ash/display/display_change_observer_chromeos.h"
 
 #include <algorithm>
 #include <map>
 #include <set>
 #include <vector>
@@ skipping 23 matching lines @@
 // Higher DPI than this will use device_scale_factor=2.
 const unsigned int kHighDensityDPIThreshold = 160;
 
 // 1 inch in mm.
 const float kInchInMm = 25.4f;
 
 // Resolution list are sorted by the area in pixels and the larger
 // one comes first.
 struct ResolutionSorter {
   bool operator()(const Resolution& a, const Resolution& b) {
-    return a.size.width() * a.size.height() > b.size.width() * b.size.height();
+    if (a.size.GetArea() == b.size.GetArea())
+      return (a.refresh_rate > b.refresh_rate);
+    return (a.size.GetArea() > b.size.GetArea());
   }
 };
 
 }  // namespace
 
 // static
 std::vector<Resolution> DisplayChangeObserver::GetResolutionList(
     const OutputConfigurator::OutputSnapshot& output) {
   typedef std::map<std::pair<int,int>, Resolution> ResolutionMap;
   ResolutionMap resolution_map;
 
   for (std::map<RRMode, OutputConfigurator::ModeInfo>::const_iterator it =
        output.mode_infos.begin(); it != output.mode_infos.end(); ++it) {
     const OutputConfigurator::ModeInfo& mode_info = it->second;
     const std::pair<int, int> size(mode_info.width, mode_info.height);
     const Resolution resolution(gfx::Size(mode_info.width, mode_info.height),
+                                mode_info.refresh_rate,
                                 mode_info.interlaced);
 
     // Add the resolution if it isn't already present and override interlaced
     // resolutions with non-interlaced ones.
     ResolutionMap::iterator resolution_it = resolution_map.find(size);
     if (resolution_it == resolution_map.end())
       resolution_map.insert(std::make_pair(size, resolution));
     else if (resolution_it->second.interlaced && !resolution.interlaced)
       resolution_it->second = resolution;
   }
@@ skipping 26 matching lines @@
   CHECK_EQ(2U, display_ids.size());
   DisplayIdPair pair = std::make_pair(display_ids[0], display_ids[1]);
   DisplayLayout layout = Shell::GetInstance()->display_manager()->
       layout_store()->GetRegisteredDisplayLayout(pair);
   return layout.mirrored ?
       chromeos::STATE_DUAL_MIRROR : chromeos::STATE_DUAL_EXTENDED;
 }
 
 bool DisplayChangeObserver::GetResolutionForDisplayId(int64 display_id,
                                                       int* width,
-                                                      int* height) const {
+                                                      int* height,
+                                                      float* refresh_rate)
+    const {
   gfx::Size resolution;
-  if (!Shell::GetInstance()->display_manager()->
-      GetSelectedResolutionForDisplayId(display_id, &resolution)) {
+  if (!Shell::GetInstance()
+           ->display_manager()
+           ->GetSelectedResolutionForDisplayId(
+                 display_id, &resolution, refresh_rate)) {
     return false;
   }
 
   *width = resolution.width();
   *height = resolution.height();
   return true;
 }
 
 void DisplayChangeObserver::OnDisplayModeChanged(
     const std::vector<OutputConfigurator::OutputSnapshot>& outputs) {
@@ skipping 17 matching lines @@
 
     float device_scale_factor = 1.0f;
     if (!ui::IsXDisplaySizeBlackListed(output.width_mm, output.height_mm) &&
         (kInchInMm * mode_info->width / output.width_mm) >
         kHighDensityDPIThreshold) {
       device_scale_factor = 2.0f;
     }
     gfx::Rect display_bounds(
         output.x, output.y, mode_info->width, mode_info->height);
 
-    std::vector<Resolution> resolutions;
-    if (output.type != chromeos::OUTPUT_TYPE_INTERNAL)
-      resolutions = GetResolutionList(output);
+    std::vector<Resolution> resolutions = GetResolutionList(output);
 
     std::string name = output.type == chromeos::OUTPUT_TYPE_INTERNAL ?
         l10n_util::GetStringUTF8(IDS_ASH_INTERNAL_DISPLAY_NAME) :
         chromeos::GetDisplayName(output.output);
     if (name.empty())
       name = l10n_util::GetStringUTF8(IDS_ASH_STATUS_TRAY_UNKNOWN_DISPLAY_NAME);
 
     bool has_overscan = false;
     chromeos::GetOutputOverscanFlag(output.output, &has_overscan);
 
@@ skipping 19 matching lines @@
 void DisplayChangeObserver::OnAppTerminating() {
 #if defined(USE_ASH)
   // Stop handling display configuration events once the shutdown
   // process starts. crbug.com/177014.
   Shell::GetInstance()->output_configurator()->Stop();
 #endif
 }
 
 }  // namespace internal
 }  // namespace ash