Media Controls: Fix time updates when dragging from track not scrubber

third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp

Index: third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
diff --git a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
index eac75ab2c736f1d7cb4132ffec13f6190a2adcc9..ef9037aeb82c3bda6591c1bb181baf02b6e89f37 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
@@ -45,9 +45,11 @@
 #include "core/html/HTMLVideoElement.h"
 #include "core/html/TimeRanges.h"
 #include "core/html/shadow/MediaControls.h"
+#include "core/html/shadow/ShadowElementNames.h"
+#include "core/html/shadow/SliderThumbElement.h"
 #include "core/html/track/TextTrackList.h"
 #include "core/input/EventHandler.h"
-#include "core/layout/api/LayoutSliderItem.h"
+#include "core/layout/LayoutObject.h"
 #include "core/page/Page.h"
 #include "platform/EventDispatchForbiddenScope.h"
 #include "platform/Histogram.h"
@@ -76,6 +78,13 @@ const QualifiedName& trackIndexAttrName() {
 // When specified as trackIndex, disable text tracks.
 const int trackIndexOffValue = -1;
 
+bool inDragMode(MediaControlInputElement* rangeInput) {
+  SliderThumbElement* thumb =
+      toSliderThumbElement(rangeInput->userAgentShadowRoot()->getElementById(
+          ShadowElementNames::sliderThumb()));
+  return thumb && thumb->inDragMode();
+}
+
 bool isUserInteractionEvent(Event* event) {
   const AtomicString& type = event->type();
   return type == EventTypeNames::mousedown || type == EventTypeNames::mouseup ||
@@ -85,15 +94,15 @@ bool isUserInteractionEvent(Event* event) {
 
 // Sliders (the volume control and timeline) need to capture some additional
 // events used when dragging the thumb.
-bool isUserInteractionEventForSlider(Event* event, LayoutObject* layoutObject) {
+bool isUserInteractionEventForSlider(Event* event,
+                                     MediaControlInputElement* rangeInput) {
   // It is unclear if this can be converted to isUserInteractionEvent(), since
   // mouse* events seem to be eaten during a drag anyway.  crbug.com/516416 .
   if (isUserInteractionEvent(event))
     return true;
 
   // Some events are only captured during a slider drag.
-  LayoutSliderItem slider = LayoutSliderItem(toLayoutSlider(layoutObject));
-  if (!slider.isNull() && !slider.inDragMode())
+  if (!inDragMode(rangeInput))
     return false;
 
   const AtomicString& type = event->type();
@@ -783,8 +792,7 @@ void MediaControlTimelineElement::defaultEventHandler(Event* event) {
   if (mediaElement().seekable()->contain(time))
     mediaElement().setCurrentTime(time);
 
-  LayoutSliderItem slider = LayoutSliderItem(toLayoutSlider(layoutObject()));
-  if (!slider.isNull() && slider.inDragMode())
+  if (inDragMode(this))
     mediaControls().updateCurrentTimeDisplay();
 }
 
@@ -807,7 +815,7 @@ void MediaControlTimelineElement::setDuration(double duration) {
 }
 
 bool MediaControlTimelineElement::keepEventInNode(Event* event) {
-  return isUserInteractionEventForSlider(event, layoutObject());
+  return isUserInteractionEventForSlider(event, this);
 }
 
 // ----------------------------
@@ -874,7 +882,7 @@ void MediaControlVolumeSliderElement::setVolume(double volume) {
 }
 
 bool MediaControlVolumeSliderElement::keepEventInNode(Event* event) {
-  return isUserInteractionEventForSlider(event, layoutObject());
+  return isUserInteractionEventForSlider(event, this);
 }
 
 // ----------------------------