Update {virtual,override,final} to follow C++11 style in ash.

ash/display/display_manager_unittest.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 "ash/display/display_manager.h"
 
 #include "ash/ash_switches.h"
 #include "ash/display/display_controller.h"
 #include "ash/display/display_info.h"
 #include "ash/display/display_layout_store.h"
@@ skipping 1558 matching lines @@
   FontTestHelper(float scale, DisplayType display_type) {
     gfx::ClearFontRenderParamsCacheForTest();
     base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
     if (display_type == INTERNAL)
       command_line->AppendSwitch(switches::kAshUseFirstDisplayAsInternal);
     command_line->AppendSwitchASCII(switches::kAshHostWindowBounds,
                                     StringPrintf("1000x800*%f", scale));
     SetUp();
   }
 
-  virtual ~FontTestHelper() {
-    TearDown();
-  }
+  ~FontTestHelper() override { TearDown(); }
 
   // test::AshTestBase:
-  virtual void TestBody() override {
-    NOTREACHED();
-  }
+  void TestBody() override { NOTREACHED(); }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FontTestHelper);
 };
 
 
 bool IsTextSubpixelPositioningEnabled() {
   gfx::FontRenderParams params =
       gfx::GetFontRenderParams(gfx::FontRenderParamsQuery(false), NULL);
   return params.subpixel_positioning;
@@ skipping 81 matching lines @@
       1.25f, Shell::GetScreen()->GetPrimaryDisplay().device_scale_factor());
   EXPECT_TRUE(IsTextSubpixelPositioningEnabled());
   EXPECT_EQ(gfx::FontRenderParams::HINTING_NONE, GetFontHintingParams());
 
   DisplayInfo::SetUse125DSFForUIScaling(false);
 }
 
 #endif  // OS_CHROMEOS
 
 }  // namespace ash