Flip the flag to enable smooth screen rotation by default.

chrome/browser/flag_descriptions.h

 // 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.
 
 #ifndef CHROME_BROWSER_FLAG_DESCRIPTIONS_H_
 #define CHROME_BROWSER_FLAG_DESCRIPTIONS_H_
 
 // Includes needed for macros allowing conditional compilation of some strings.
 #include "build/build_config.h"
 #include "build/buildflag.h"
@@ skipping 811 matching lines @@
 // Description for the flag which can be used for support for javascript locking
 // rotation
 extern const char kAshScreenOrientationLockDescription[];
 
 // Title for the flag to enable the mirrored screen mode.
 extern const char kAshEnableMirroredScreenName[];
 
 // Description for the flag to enable the mirrored screen mode.
 extern const char kAshEnableMirroredScreenDescription[];
 
-// Title for the flag to enable smooth rotation animations.
-extern const char kAshEnableSmoothScreenRotationName[];
+// Title for the flag to disable smooth rotation animations.
+extern const char kAshDisableSmoothScreenRotationName[];
 
-// Description for the flag to enable smooth rotation animations.
-extern const char kAshEnableSmoothScreenRotationDescription[];
+// Description for the flag to disable smooth rotation animations.
+extern const char kAshDisableSmoothScreenRotationDescription[];
 
 // Description for the flag that sets material design ink drop animation speed
 // of fast.
 extern const char kMaterialDesignInkDropAnimationFast[];
 
 // Description for the flag that sets material design ink drop anation speeds of
 // slow.
 extern const char kMaterialDesignInkDropAnimationSlow[];
 
 // Name for the flag that sets the material design ink drop animation speed.
@@ skipping 2469 matching lines @@
 extern const char kEnableOmniboxClipboardProviderName[];
 
 // Description of the flag that enables the omnibox's clipboard URL provider.
 extern const char kEnableOmniboxClipboardProviderDescription[];
 
 #endif  // defined(OS_ANDROID)
 
 }  // namespace flag_descriptions
 
 #endif  // CHROME_BROWSER_FLAG_DESCRIPTIONS_H_