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

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

 /*
  * 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 563 matching lines @@
 }
 
 void MediaControlsImpl::MaybeShow() {
   panel_->SetIsWanted(true);
   panel_->SetIsDisplayed(true);
   if (overlay_play_button_)
     overlay_play_button_->UpdateDisplayType();
   // Only make the controls visible if they won't get hidden by OnTimeUpdate.
   if (MediaElement().paused() || !ShouldHideMediaControls())
     MakeOpaque();
+  download_button_->UpdateInProductHelpState();

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

`MakeOpaque()` is what you care about here. I'm afraid you might end up showing
the IPH without the controls being visible.

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

So I think I wasn't understanding the 2 states on the controls clearly. The
element enables/disables showing of the controls using MaybeShow/Hide. And then
the controls internally manage making themselves visible using
MakeOpaque/transparent. We don't want to show IPH if the controls have been
hidden using Hide(). But we can make them visible for the purpose of showing it.

I updated the MayBeDispatchInProductHelpTrigger to happen only when the panel
IsWanted. And we need to dismiss this IPH if the controls are hidden so Hide is
the only thing that needs to dismiss it. Restructured the code in the button as
well to make this obvious.

 }
 
 void MediaControlsImpl::Hide() {
   panel_->SetIsWanted(false);
   panel_->SetIsDisplayed(false);
   if (overlay_play_button_)
     overlay_play_button_->SetIsWanted(false);
+  download_button_->UpdateInProductHelpState();
 }
 
 bool MediaControlsImpl::IsVisible() const {
   return panel_->IsOpaque();
 }
 
 void MediaControlsImpl::MakeOpaque() {
   panel_->MakeOpaque();
 }
 
@@ skipping 35 matching lines @@
   const bool ignore_focus = behavior_flags & kIgnoreFocus;
   if (!ignore_focus && (MediaElement().IsFocused() ||
                         contains(GetDocument().FocusedElement()))) {
     return false;
   }
 
   // Don't hide the media controls when a panel is showing.
   if (text_track_list_->IsWanted() || overflow_list_->IsWanted())
     return false;
 
+  // Don't hide the media controls while the in product help is showing.
+  if (download_button_->IsShowingInProductHelp())
+    return false;
+
   return true;
 }
 
 void MediaControlsImpl::UpdatePlayState() {
   if (is_paused_for_scrubbing_)
     return;
 
   if (overlay_play_button_)
     overlay_play_button_->UpdateDisplayType();
   play_button_->UpdateDisplayType();
@@ skipping 308 matching lines @@
   UpdateCurrentTimeDisplay();
 
   // Update the timeline (the UI with the seek marker).
   timeline_->SetDuration(duration);
 }
 
 void MediaControlsImpl::OnPlay() {
   UpdatePlayState();
   timeline_->SetPosition(MediaElement().currentTime());
   UpdateCurrentTimeDisplay();
+  download_button_->MaybeDispatchInProductHelpTrigger();
 }
 
 void MediaControlsImpl::OnPlaying() {
   timeline_->OnPlaying();
 
   StartHideMediaControlsTimer();
 }
 
 void MediaControlsImpl::OnPause() {
   UpdatePlayState();
@@ skipping 225 matching lines @@
 
 void MediaControlsImpl::HideAllMenus() {
   window_event_listener_->Stop();
 
   if (overflow_list_->IsWanted())
     overflow_list_->SetIsWanted(false);
   if (text_track_list_->IsWanted())
     text_track_list_->SetVisible(false);
 }
 
+void MediaControlsImpl::HideControlsIfNecessary() {
+  if (ShouldHideMediaControls())
+    StartHideMediaControlsTimer();

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

There is at least one other place with this logic. Can you refactor?

Maybe rename the method `StartHideMediaControlsIfNecessary()`

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

Done.

+}
+
 DEFINE_TRACE(MediaControlsImpl) {
   visitor->Trace(element_mutation_callback_);
   visitor->Trace(resize_observer_);
   visitor->Trace(panel_);
   visitor->Trace(overlay_play_button_);
   visitor->Trace(overlay_enclosure_);
   visitor->Trace(play_button_);
   visitor->Trace(current_time_display_);
   visitor->Trace(timeline_);
   visitor->Trace(mute_button_);
@@ skipping 10 matching lines @@
   visitor->Trace(overlay_cast_button_);
   visitor->Trace(media_event_listener_);
   visitor->Trace(window_event_listener_);
   visitor->Trace(orientation_lock_delegate_);
   visitor->Trace(rotate_to_fullscreen_delegate_);
   MediaControls::Trace(visitor);
   HTMLDivElement::Trace(visitor);
 }
 
 }  // namespace blink