Ensure LayoutMedia notifies MediaControls of panel width

third_party/WebKit/Source/core/layout/LayoutMedia.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 65 matching lines @@
 
     // TODO(mlamouri): we miss some layouts because needsLayout returns false in
     // some cases where we want to change the width of the controls because the
     // visible viewport has changed for example.
     if (newRect.size() == oldSize && !child->needsLayout())
       continue;
 
     LayoutUnit width = newRect.width();
     if (child->node()->isMediaControls()) {
       width = computePanelWidth(newRect);
-      if (width != oldSize.width())
-        newPanelWidth = width;
+      newPanelWidth = width;
     }
 
     LayoutBox* layoutBox = toLayoutBox(child);
     layoutBox->setLocation(newRect.location());
     // TODO(foolip): Remove the mutableStyleRef() and depend on CSS
     // width/height: inherit to match the media element size.
     layoutBox->mutableStyleRef().setHeight(Length(newRect.height(), Fixed));
     layoutBox->mutableStyleRef().setWidth(Length(width, Fixed));
 
     layoutBox->forceLayout();
   }
 
   clearNeedsLayout();
 
   // Notify our MediaControls that a layout has happened.
   if (mediaElement() && mediaElement()->mediaControls() &&
       newPanelWidth.has_value()) {
-    mediaElement()->mediaControls()->notifyPanelWidthChanged(
-        newPanelWidth.value());
+    if (!m_lastReportedPanelWidth.has_value() ||
+        m_lastReportedPanelWidth.value() != newPanelWidth.value()) {
+      mediaElement()->mediaControls()->notifyPanelWidthChanged(
+          newPanelWidth.value());
+      // store the last value we reported, so we know if it has changed

[whywhat, 2016/12/08 23:21:06]

nit: Use proper sentence format for consistency (start with a capital and end
with a dot).

[billorr, 2016/12/08 23:34:58]

Done.

+      m_lastReportedPanelWidth = newPanelWidth.value();
+    }
   }
 }
 
 bool LayoutMedia::isChildAllowed(LayoutObject* child,
                                  const ComputedStyle&) const {
   // Two types of child layout objects are allowed: media controls
   // and the text track container. Filter children by node type.
   ASSERT(child->node());
 
   // The user agent stylesheet (mediaControls.css) has
@@ skipping 43 matching lines @@
           .x());
   const LayoutUnit newWidth = visibleWidth - absoluteXOffset;
 
   if (newWidth < 0)
     return mediaRect.width();
 
   return std::min(mediaRect.width(), visibleWidth - absoluteXOffset);
 }
 
 }  // namespace blink