Read compositor VSync information from platform, when possible

ash/display/display_manager_unittest.cc

Index: ash/display/display_manager_unittest.cc
diff --git a/ash/display/display_manager_unittest.cc b/ash/display/display_manager_unittest.cc
index 9156c20f23731587e8f9d1febc51bf940b609fdf..51ccad21711b47eef65d948cfb68127a28099cf5 100644
--- a/ash/display/display_manager_unittest.cc
+++ b/ash/display/display_manager_unittest.cc
@@ -720,9 +720,9 @@ TEST_F(DisplayManagerTest, DontRememberBestResolution) {
   DisplayInfo native_display_info =
       CreateDisplayInfo(display_id, gfx::Rect(0, 0, 1000, 500));
   std::vector<Resolution> resolutions;
-  resolutions.push_back(Resolution(gfx::Size(1000, 500), false));
-  resolutions.push_back(Resolution(gfx::Size(800, 300), false));
-  resolutions.push_back(Resolution(gfx::Size(400, 500), false));
+  resolutions.push_back(Resolution(gfx::Size(1000, 500), 58.0f, false));
+  resolutions.push_back(Resolution(gfx::Size(800, 300), 59.0f, false));
+  resolutions.push_back(Resolution(gfx::Size(400, 500), 60.0f, false));
 
   native_display_info.set_resolutions(resolutions);
 
@@ -731,24 +731,32 @@ TEST_F(DisplayManagerTest, DontRememberBestResolution) {
   display_manager()->OnNativeDisplaysChanged(display_info_list);
 
   gfx::Size selected;
-  EXPECT_FALSE(display_manager()->GetSelectedResolutionForDisplayId(
-      display_id, &selected));
+  float refresh_rate = 0.0f;
+  EXPECT_TRUE(display_manager()->GetSelectedResolutionForDisplayId(
+      display_id, &selected, &refresh_rate));
+  EXPECT_EQ("1000x500", selected.ToString());
+  EXPECT_EQ(58.0f, refresh_rate);
 
   // Unsupported resolution.
   display_manager()->SetDisplayResolution(display_id, gfx::Size(800, 4000));
-  EXPECT_FALSE(display_manager()->GetSelectedResolutionForDisplayId(
-      display_id, &selected));
+  EXPECT_TRUE(display_manager()->GetSelectedResolutionForDisplayId(
+      display_id, &selected, &refresh_rate));
+  EXPECT_EQ("1000x500", selected.ToString());
+  EXPECT_EQ(58.0f, refresh_rate);
 
   // Supported resolution.
   display_manager()->SetDisplayResolution(display_id, gfx::Size(800, 300));
   EXPECT_TRUE(display_manager()->GetSelectedResolutionForDisplayId(
-      display_id, &selected));
+      display_id, &selected, &refresh_rate));
   EXPECT_EQ("800x300", selected.ToString());
+  EXPECT_EQ(59.0f, refresh_rate);
 
   // Best resolution.
   display_manager()->SetDisplayResolution(display_id, gfx::Size(1000, 500));
-  EXPECT_FALSE(display_manager()->GetSelectedResolutionForDisplayId(
-      display_id, &selected));
+  EXPECT_TRUE(display_manager()->GetSelectedResolutionForDisplayId(
+      display_id, &selected, &refresh_rate));
+  EXPECT_EQ("1000x500", selected.ToString());
+  EXPECT_EQ(58.0f, refresh_rate);
 }
 
 TEST_F(DisplayManagerTest, ResolutionFallback) {
@@ -756,9 +764,9 @@ TEST_F(DisplayManagerTest, ResolutionFallback) {
   DisplayInfo native_display_info =
       CreateDisplayInfo(display_id, gfx::Rect(0, 0, 1000, 500));
   std::vector<Resolution> resolutions;
-  resolutions.push_back(Resolution(gfx::Size(1000, 500), false));
-  resolutions.push_back(Resolution(gfx::Size(800, 300), false));
-  resolutions.push_back(Resolution(gfx::Size(400, 500), false));
+  resolutions.push_back(Resolution(gfx::Size(1000, 500), 58.0f, false));
+  resolutions.push_back(Resolution(gfx::Size(800, 300), 59.0f, false));
+  resolutions.push_back(Resolution(gfx::Size(400, 500), 60.0f, false));
 
   std::vector<Resolution> copy = resolutions;
   native_display_info.set_resolutions(copy);
@@ -777,12 +785,14 @@ TEST_F(DisplayManagerTest, ResolutionFallback) {
     display_manager()->OnNativeDisplaysChanged(new_display_info_list);
 
     gfx::Size selected;
+    float refresh_rate = 0.0f;
     EXPECT_TRUE(display_manager()->GetSelectedResolutionForDisplayId(
-        display_id, &selected));
+        display_id, &selected, &refresh_rate));
     EXPECT_EQ("400x500", selected.ToString());
+    EXPECT_EQ(60.0f, refresh_rate);
   }
   {
-    // Best resolution should not be set.
+    // Best resolution should find itself on the resolutions list.
     display_manager()->SetDisplayResolution(display_id, gfx::Size(800, 300));
     DisplayInfo new_native_display_info =
         CreateDisplayInfo(display_id, gfx::Rect(0, 0, 1000, 500));
@@ -793,8 +803,11 @@ TEST_F(DisplayManagerTest, ResolutionFallback) {
     display_manager()->OnNativeDisplaysChanged(new_display_info_list);
 
     gfx::Size selected;
-    EXPECT_FALSE(display_manager()->GetSelectedResolutionForDisplayId(
-        display_id, &selected));
+    float refresh_rate = 0.0f;
+    EXPECT_TRUE(display_manager()->GetSelectedResolutionForDisplayId(
+        display_id, &selected, &refresh_rate));
+    EXPECT_EQ("1000x500", selected.ToString());
+    EXPECT_EQ(58.0f, refresh_rate);
   }
 }