[Media Controls] Prevent fullscreen orientation lock rotate glitch

third_party/WebKit/Source/modules/media_controls/MediaControlsOrientationLockDelegate.h

 // Copyright 2016 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 MediaControlsOrientationLockDelegate_h
 #define MediaControlsOrientationLockDelegate_h
 
 #include "core/events/EventListener.h"
 #include "device/screen_orientation/public/interfaces/screen_orientation.mojom-blink.h"
 #include "modules/ModulesExport.h"
+#include "platform/WebTaskRunner.h"
 #include "public/platform/modules/screen_orientation/WebScreenOrientationLockType.h"
 
 namespace blink {
 
 class DeviceOrientationData;
 class DeviceOrientationEvent;
 class Document;
 class HTMLVideoElement;
 
 // MediaControlsOrientationLockDelegate is implementing the orientation lock
@@ skipping 85 matching lines @@
   void MaybeUnlockOrientation();
 
   void MaybeListenToDeviceOrientation();
   void GotIsAutoRotateEnabledByUser(bool enabled);
 
   MODULES_EXPORT DeviceOrientation
   ComputeDeviceOrientation(DeviceOrientationData*) const;
 
   void MaybeUnlockIfDeviceOrientationMatchesVideo(DeviceOrientationEvent*);
 
+  // Delay before unlocking - see `MaybeUnlockIfDeviceOrientationMatchesVideo`.
+  // Emprically, 200ms is too short, but 250ms avoids glitches. 500ms gives us
+  // a 2x margin in case the device is running slow, without being noticeable.
+  static constexpr int kUnlockDelayMs = 500;
+
   // Current state of the object. See comment at the top of the file for a
   // detailed description.
   State state_ = State::kPendingFullscreen;
 
   // Which lock is currently applied by this delegate.
   WebScreenOrientationLockType locked_orientation_ =
       kWebScreenOrientationLockDefault /* unlocked */;
 
+  TaskHandle unlock_task_;
+
   device::mojom::blink::ScreenOrientationListenerPtr monitor_;
 
   int is_auto_rotate_enabled_by_user_for_testing_ = -1;
 
   // `video_element_` owns MediaControlsImpl that owns |this|.
   Member<HTMLVideoElement> video_element_;
 };
 
 }  // namespace blink
 
 #endif  // MediaControlsOrientationLockDelegate_h