Add flags to enable screen orientation lock for fullscreen video on Android.

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index f24005eeb1c8b0f1f32594029d72251e85cc96c4..d6fc850869696de278e04569d34071cbf0c456f0 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -15550,6 +15550,14 @@ read aloud to screenreader users to announce that a completion is available.">
       Disable video tracks when the video is played in the background to optimize performance.
     </message>
 
+    <!-- Video fullscreen with orientation lock experiment strings. -->
+    <message name="IDS_FLAGS_VIDEO_FULLSCREEN_ORIENTATION_LOCK_NAME" desc="Name of the flag for enabling orientation lock for fullscreen video playback.">
+      Lock screen orientation when playing a video fullscreen.
+    </message>
+    <message name="IDS_FLAGS_VIDEO_FULLSCREEN_ORIENTATION_LOCK_DESCRIPTION" desc="Description of the flag for enabling orientation lock for fullscreen video playback.">
+      Lock the screen orientation of the device to match video orientation when a video goes fullscreen.
+    </message>
+
     <if expr="is_win">
       <message name="IDS_UTILITY_PROCESS_SHELL_HANDLER_NAME" desc="The name of the utility process used to handle shell operations.">
         Shell Handler