media_controls: Add UI for showing a promo bubble on a control button.

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 b9759b9c1d2ca450f46ac128d4bc041e0a890b83..c7790037fbe14443436504c6d48cfa5fbc216564 100644
--- a/third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.cpp
+++ b/third_party/WebKit/Source/modules/media_controls/elements/MediaControlDownloadButtonElement.cpp
@@ -18,6 +18,17 @@
 
 namespace blink {
 
+MediaControlDownloadButtonContainer::MediaControlDownloadButtonContainer(
+    MediaControlsImpl& controls)
+    : MediaControlDivElement(controls, kMediaDownloadButtonContainer) {
+  SetShadowPseudoId(
+      AtomicString("-internal-media-controls-download-button-container"));
+}
+
+bool MediaControlDownloadButtonContainer::KeepEventInNode(Event* event) {
+  return MediaControlElementsHelper::IsUserInteractionEvent(event);
+}
+
 MediaControlDownloadButtonElement::MediaControlDownloadButtonElement(
     MediaControlsImpl& media_controls)
     : MediaControlInputElement(media_controls, kMediaDownloadButton) {