chrome/blink: Add functionality for in-product help for media elements.

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

 /*
  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 102 matching lines @@
   void ToggleOverflowMenu();
   bool OverflowMenuVisible();
 
   void ShowOverlayCastButtonIfNeeded();
 
   // Methods call by the scrubber.
   void BeginScrubbing();
   void EndScrubbing();
   void UpdateCurrentTimeDisplay();
 
+  bool CanShow() const;

[mlamouri (slow - plz ping), 2017/07/25 17:29:08]

What does that mean?

[Khushal, 2017/08/03 02:41:21]

It returns the status of the panel. That is, whether the controls have been
hidden externally using Hide versus internal timer-based hiding. If its the
former, then we don't show the IPH. But if its the latter, then we can
internally make the controls visible for showing it.

+  bool IsVisible() const;
+  void StartHideMediaControlsIfNecessary();
+
   DECLARE_VIRTUAL_TRACE();
 
  private:
   // MediaControlsMediaEventListener is a component that is listening to events
   // and calling the appropriate callback on MediaControlsImpl. The object is
   // split from MedaiControlsImpl to reduce boilerplate and ease reading. In
   // order to not expose accessors only for this component, a friendship is
   // declared.
   friend class MediaControlsMediaEventListener;
   // Same as above but handles the menus hiding when the window is interacted
@@ skipping 17 matching lines @@
 
   // Notify us that our controls enclosure has changed size.
   void NotifyElementSizeChanged(DOMRectReadOnly* new_size);
 
   explicit MediaControlsImpl(HTMLMediaElement&);
 
   void InitializeControls();
 
   void MakeOpaque();
   void MakeTransparent();
-  bool IsVisible() const;
 
   void UpdatePlayState();
 
   enum HideBehaviorFlags {
     kIgnoreNone = 0,
     kIgnoreVideoHover = 1 << 0,
     kIgnoreFocus = 1 << 1,
     kIgnoreControlsHover = 1 << 2,
     kIgnoreWaitForTimer = 1 << 3,
   };
@@ skipping 86 matching lines @@
   IntSize size_;
 
   bool keep_showing_until_timer_fires_ : 1;
 };
 
 DEFINE_ELEMENT_TYPE_CASTS(MediaControlsImpl, IsMediaControls());
 
 }  // namespace blink
 
 #endif