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

third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.cpp

 // Copyright 2017 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.
 
 #include "modules/media_controls/elements/MediaControlDownloadButtonElement.h"
 
 #include "core/InputTypeNames.h"
 #include "core/events/Event.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLAnchorElement.h"
@@ skipping 73 matching lines @@
 bool MediaControlDownloadButtonElement::HasOverflowButton() {
   return true;
 }
 
 void MediaControlDownloadButtonElement::SetIsWanted(bool wanted) {
   MediaControlElement::SetIsWanted(wanted);
 
   if (!IsWanted())
     return;
 
-  DCHECK(IsWanted());
   if (!show_use_counted_) {
     show_use_counted_ = true;
     RecordMetrics(DownloadActionMetrics::kShown);
   }
+
+  // If the button is wanted, show IPH if possible.
+  static_cast<MediaControlsImpl&>(GetMediaControls())
+      .MaybeDispatchDownloadIPHTrigger();
 }
 
 DEFINE_TRACE(MediaControlDownloadButtonElement) {
   visitor->Trace(anchor_);
   MediaControlInputElement::Trace(visitor);
 }
 
 void MediaControlDownloadButtonElement::DefaultEventHandler(Event* event) {
   const KURL& url = MediaElement().currentSrc();
   if (event->type() == EventTypeNames::click &&
@@ skipping 17 matching lines @@
 
 void MediaControlDownloadButtonElement::RecordMetrics(
     DownloadActionMetrics metric) {
   DEFINE_STATIC_LOCAL(EnumerationHistogram, download_action_histogram,
                       ("Media.Controls.Download",
                        static_cast<int>(DownloadActionMetrics::kCount)));
   download_action_histogram.Count(static_cast<int>(metric));
 }
 
 }  // namespace blink