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

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

Index: third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h
diff --git a/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h b/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h
index c8bba03406999ebcf2a926da86f0cb5d7b5ef120..c27f3160c4ce9257a7b46c758f23545d217db108 100644
--- a/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h
+++ b/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h
@@ -120,6 +120,9 @@ class MODULES_EXPORT MediaControlsImpl final : public HTMLDivElement,
   void EndScrubbing();
   void UpdateCurrentTimeDisplay();
 
+  bool IsVisible() const;
+  void HideControlsIfNecessary();

[mlamouri (slow - plz ping), 2017/07/13 21:14:27]

Having the buttons being able to hide the control bar is bothering but I can't
find a better alternative. Could you maybe add a comment explaining why these
two methods are public?

[Khushal, 2017/07/17 17:52:20]

The controls will still check the internal state and only hide if it is valid to
do so? Is there a reason why it would still be a concern to have this function
public?

+
   DECLARE_VIRTUAL_TRACE();
 
  private:
@@ -157,7 +160,6 @@ class MODULES_EXPORT MediaControlsImpl final : public HTMLDivElement,
 
   void MakeOpaque();
   void MakeTransparent();
-  bool IsVisible() const;
 
   void UpdatePlayState();