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

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

Index: third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.h
diff --git a/third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.h b/third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.h
index ca65918220c86784d8162af10f67bb5d941f496c..8e49c3bddda86e1bcf3c443b565ee0de43be2e84 100644
--- a/third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.h
+++ b/third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.h
@@ -5,14 +5,17 @@
 #ifndef MediaControlDownloadButtonElement_h
 #define MediaControlDownloadButtonElement_h
 
+#include "modules/ModulesExport.h"
 #include "modules/media_controls/elements/MediaControlInputElement.h"
 
+#include "public/platform/media_download_in_product_help.mojom-blink.h"
+
 namespace blink {
 
 class Event;
 class MediaControlsImpl;
 
-class MediaControlDownloadButtonElement final
+class MODULES_EXPORT MediaControlDownloadButtonElement final
     : public MediaControlInputElement {
  public:
   explicit MediaControlDownloadButtonElement(MediaControlsImpl&);
@@ -21,6 +24,10 @@ class MediaControlDownloadButtonElement final
   // show the button for only non-MSE, non-EME, and non-MediaStream content.
   bool ShouldDisplayDownloadButton();
 
+  void DismissInProductHelp();
+  void MaybeDispatchInProductHelpTrigger();
+  bool IsShowingInProductHelp() const;
+
   // MediaControlInputElement overrides.
   // TODO(mlamouri): add WillRespondToMouseClickEvents
   WebLocalizedString::Name GetOverflowStringName() const override;
@@ -49,6 +56,10 @@ class MediaControlDownloadButtonElement final
   // for the same media element.
   bool click_use_counted_ = false;
   bool show_use_counted_ = false;
+
+  std::unique_ptr<mojom::blink::MediaDownloadInProductHelpPtr>
+      media_in_product_help_;
+  bool media_download_in_product_trigger_observed_ = false;
 };
 
 }  // namespace blink