Uses copy request to flatten the layers to do screen rotation animation.

chrome/browser/flag_descriptions.cc

 // Copyright 2017 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 "chrome/browser/flag_descriptions.h"
 
 namespace flag_descriptions {
 
 //  Material Design version of chrome://bookmarks
 
@@ skipping 704 matching lines @@
 
 const char kAshScreenOrientationLockDescription[] =
     "Allows javascript to lock the screen orienation.";
 
 const char kAshEnableMirroredScreenName[] = "Enable mirrored screen mode.";
 
 const char kAshEnableMirroredScreenDescription[] =
     "Enable the mirrored screen mode. This mode flips the screen image "
     "horizontally.";
 
+const char kAshEnableSmoothScreenRotationName[] =
+    "Enable smooth rotation animations.";
+
+const char kAshEnableSmoothScreenRotationDescription[] =
+    "Enable smooth rotation animations.";
+
 const char kMaterialDesignInkDropAnimationFast[] = "Fast";
 
 const char kMaterialDesignInkDropAnimationSlow[] = "Slow";
 
 const char kMaterialDesignInkDropAnimationSpeedName[] =
     "Material Design Ink Drop Animation Speed";
 
 const char kMaterialDesignInkDropAnimationSpeedDescription[] =
     "Sets the speed of the experimental visual feedback animations for "
     "material design.";
@@ skipping 2165 matching lines @@
 const char kEnableEhvInputName[] =
     "Emoji, handwriting and voice input on opt-in IME menu";
 
 const char kEnableEhvInputDescription[] =
     "Enable access to emoji, handwriting and voice input form opt-in IME "
     "menu.";
 
 #endif  // #if defined(OS_CHROMEOS)
 
 }  // namespace flag_descriptions