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

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

Index: third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.cpp
diff --git a/third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.cpp b/third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.cpp
index f7a9f8f05c581e16d097cdb60ff5599fbb36acc9..a1e8fe99122138700c18d6148cd88c203e72a56f 100644
--- a/third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.cpp
+++ b/third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.cpp
@@ -6,6 +6,7 @@
 
 #include "core/InputTypeNames.h"
 #include "core/events/Event.h"
+#include "core/frame/LocalFrameClient.h"

[mlamouri (slow - plz ping), 2017/08/16 13:09:30]

Looks like you don't need this include anymore.

[Khushal, 2017/08/16 19:01:23]

Done.

 #include "core/frame/Settings.h"
 #include "core/html/HTMLAnchorElement.h"
 #include "core/html/HTMLMediaElement.h"
@@ -13,6 +14,8 @@
 #include "core/html/media/HTMLMediaSource.h"
 #include "core/page/Page.h"
 #include "modules/media_controls/MediaControlsImpl.h"
+#include "modules/media_controls/MediaDownloadInProductHelpManager.h"
+#include "platform/wtf/Functional.h"

[mlamouri (slow - plz ping), 2017/08/16 13:09:30]

Do you still need Functional.h?

[Khushal, 2017/08/16 19:01:22]

Nope.

 #include "public/platform/Platform.h"
 
 namespace blink {
@@ -93,6 +96,15 @@ const char* MediaControlDownloadButtonElement::GetNameForHistograms() const {
   return IsOverflowElement() ? "DownloadOverflowButton" : "DownloadButton";
 }
 
+void MediaControlDownloadButtonElement::UpdateShownState() {
+  MediaControlInputElement::UpdateShownState();
+
+  auto* iph_manager = static_cast<MediaControlsImpl&>(GetMediaControls())

[mlamouri (slow - plz ping), 2017/08/16 13:09:30]

You shouldn't have to static_cast anymore. Also, do you really need the `auto`
here?

[Khushal, 2017/08/16 19:01:22]

That's great. Remove the auto. I had it earlier because I didn't want to do the
ugly static_cast multiple times.

+                          .DownloadInProductHelp();
+  if (iph_manager)
+    iph_manager->SetDownloadButtonState(IsWanted() && DoesFit());

[mlamouri (slow - plz ping), 2017/08/16 13:09:30]

Maybe you should call this `SetDownloadButtonVisible()` because it wasn't clear
to me which state you were passing until I read the implementation.

[Khushal, 2017/08/16 19:01:23]

Done.

+}
+
 void MediaControlDownloadButtonElement::DefaultEventHandler(Event* event) {
   const KURL& url = MediaElement().currentSrc();
   if (event->type() == EventTypeNames::click &&