Rename Document::ownerElement to localOwner and fix main frame checks.

third_party/WebKit/Source/core/input/EventHandler.cpp

Index: third_party/WebKit/Source/core/input/EventHandler.cpp
diff --git a/third_party/WebKit/Source/core/input/EventHandler.cpp b/third_party/WebKit/Source/core/input/EventHandler.cpp
index dbc20349449fedba842cf2c85959f0cd7ceda670..eac81066d1f62eac05b8760e5d69a1d86e058166 100644
--- a/third_party/WebKit/Source/core/input/EventHandler.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandler.cpp
@@ -84,6 +84,7 @@
 #include "core/page/SpatialNavigation.h"
 #include "core/page/TouchAdjustment.h"
 #include "core/page/scrolling/OverscrollController.h"
+#include "core/page/scrolling/RootScroller.h"
 #include "core/page/scrolling/ScrollState.h"
 #include "core/paint/PaintLayer.h"
 #include "core/style/ComputedStyle.h"
@@ -2429,11 +2430,10 @@ bool EventHandler::isRootScroller(const Node& node) const
 {
     // The root scroller is the one Element on the page designated to perform
     // "viewport actions" like top controls movement and overscroll glow.
-
-    if (!node.isElementNode() || node.document().ownerElement())
+    if (!node.isElementNode() || !frameHost() || !frameHost()->rootScroller())
         return false;
 
-    return node.document().rootScroller() == toElement(&node);
+    return frameHost()->rootScroller()->get() == toElement(&node);

[esprehn, 2016/05/09 21:22:34]

you don't need to cast a node to an Element to compare it. Also this whole
function is:

if (!frameHost())
  return false;
return frameHost()->rootScroller() == node;

[bokan, 2016/05/09 22:26:18]

Done, but this will break silently if Element or ContainerNode ever multiply
inherit from an additional class before Node. Do we disallow MI with data
members?
The rootScroller check is needed since it can be null in the OOPIF case right
now. 

 }
 
 WebInputEventResult EventHandler::handleGestureScrollUpdate(const PlatformGestureEvent& gestureEvent)
@@ -3708,6 +3708,12 @@ PlatformEvent::Modifiers EventHandler::accessKeyModifiers()
 
 FrameHost* EventHandler::frameHost()
 {
+    return const_cast<FrameHost*>(
+        static_cast<const EventHandler&>(*this).frameHost());

[esprehn, 2016/05/09 21:22:34]

woah, just mark the getter as const

[bokan, 2016/05/09 22:26:18]

Done.

+}
+
+const FrameHost* EventHandler::frameHost() const

[esprehn, 2016/05/09 21:22:34]

no need for this, the getter can just be const

[dcheng, 2016/05/09 21:26:16]

I think we should just make this FrameHost* EventHandler::frameHost() const, for
consistency with the rest of Blink (e.g. the ownerElement method renamed in this
CL is a const-method returning a non-const pointer still).

I think it's unlikely we're going to want this pattern in Blink, unless someone
can figure out what this would look like and what the benefits would be.

[bokan, 2016/05/09 22:26:18]

Done.

+{
     if (!m_frame->page())
         return nullptr;