Fix crash when computing media controls width for out of process iframe

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

Index: third_party/WebKit/Source/core/layout/LayoutMedia.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutMedia.cpp b/third_party/WebKit/Source/core/layout/LayoutMedia.cpp
index ec6bad08ae71453cc5c87243ecbb1eb4c266616d..75a8f98710baf0c81cad9c56a7176c253d3b4f54 100644
--- a/third_party/WebKit/Source/core/layout/LayoutMedia.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutMedia.cpp
@@ -159,6 +159,11 @@ void LayoutMedia::setRequestPositionUpdates(bool want) {
 }
 
 LayoutUnit LayoutMedia::computePanelWidth(const LayoutRect& mediaRect) const {
+  // We don't know if the main frame has an horizontal scrollbar if it is out of
+  // process.
+  if (document().page()->mainFrame()->isRemoteFrame())

[dcheng, 2016/11/04 16:48:36]

What breaks if we don't go through the rest of this path for OOPIF? Do we need
to handle that case at some point?

[mlamouri (slow - plz ping), 2016/11/04 17:00:56]

The feature is meant to make the default controls resize to match the viewport
if the user can't scroll horizontally. It's mostly targeted for mobile (but
would work on desktop though). On OOPIF, it would behave exactly like today
where part of the controls are not visible. It's not ideal but not a serious
concerns especially given that OOPIF might not be enabled on Android any time
soon, right?

[mlamouri (slow - plz ping), 2016/11/04 18:17:55]

Do you want me to file a bug and add a TODO?

+    return mediaRect.width();
+
   FrameHost* frameHost = document().frameHost();
   LocalFrame* mainFrame = document().page()->deprecatedLocalMainFrame();
   FrameView* pageView = mainFrame ? mainFrame->view() : nullptr;