[Media controls] Add rotate-to-fullscreen gesture behind flag

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 2794 matching lines @@
 
 //  Video fullscreen with orientation lock experiment strings.
 
 // Name of the flag for enabling orientation lock for fullscreen video playback.
 extern const char kVideoFullscreenOrientationLockName[];
 
 // Description of the flag for enabling orientation lock for fullscreen video
 // playback.
 extern const char kVideoFullscreenOrientationLockDescription[];
 
+//  Video rotate-to-fullscreen experiment strings.
+
+// Name of the flag for enabling rotate-to-fullscreen for video playback.
+extern const char kVideoRotateToFullscreenName[];
+
+// Description of the flag for enabling rotate-to-fullscreen for video playback.
+extern const char kVideoRotateToFullscreenDescription[];
+
 //  Expensive background timer throttling flag
 
 // Name for the flag to enable expensive background timer throttling
 extern const char kExpensiveBackgroundTimerThrottlingName[];
 
 // Description for the flag to enable expensive background timer throttling
 extern const char kExpensiveBackgroundTimerThrottlingDescription[];
 
 //  Enable default MediaSession flag
 
@@ skipping 485 matching lines @@
 
 // Description of the autoplay policy that has no user gesture requirements.
 extern const char kAutoplayPolicyNoUserGestureRequired[];
 
 // Description of the autoplay policy that requires a user gesture.
 extern const char kAutoplayPolicyUserGestureRequired[];
 
 }  // namespace flag_descriptions
 
 #endif  // CHROME_BROWSER_FLAG_DESCRIPTIONS_H_