Ensure RemoteViewportIntersection rect persists across frame navigations

third_party/WebKit/Source/core/frame/LocalFrame.cpp

Index: third_party/WebKit/Source/core/frame/LocalFrame.cpp
diff --git a/third_party/WebKit/Source/core/frame/LocalFrame.cpp b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
index 3eefa4fb1b4e989b32a932a7221951863416ce44..7cafbe02ce0e9dfedff7e7523c0dea7409fc8e7e 100644
--- a/third_party/WebKit/Source/core/frame/LocalFrame.cpp
+++ b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
@@ -1201,4 +1201,13 @@ WebPluginContainerBase* LocalFrame::GetWebPluginContainerBase(
   return nullptr;
 }
 
+void LocalFrame::SetViewportIntersectionFromParent(
+    const IntRect& viewport_intersection) {
+  if (remote_viewport_intersection_ != viewport_intersection) {
+    remote_viewport_intersection_ = viewport_intersection;
+    if (View())
+      View()->ScheduleAnimation();

[dcheng, 2017/05/30 19:54:11]

Btw, why do we need to call ScheduleAnimation() here?

[kenrb, 2017/05/30 21:19:21]

It causes intersection recalculations through all the FrameViews. It affects
frame throttling, as well as causing updated viewport intersection rects to be
sent to any OOPIFs nested within this one.

[dcheng, 2017/05/30 22:14:26]

I guess the name just feels a little funny.

+  }
+}
+
 }  // namespace blink