Propagate auto-resize viewport values to OOPIF processes

content/browser/frame_host/render_widget_host_view_child_frame.cc

Index: content/browser/frame_host/render_widget_host_view_child_frame.cc
diff --git a/content/browser/frame_host/render_widget_host_view_child_frame.cc b/content/browser/frame_host/render_widget_host_view_child_frame.cc
index cbd72586e4244e8d7bb4e0cbe291f49933a9830c..7c8c5f64214cb92dad2572b3ca672b69b9fca7ff 100644
--- a/content/browser/frame_host/render_widget_host_view_child_frame.cc
+++ b/content/browser/frame_host/render_widget_host_view_child_frame.cc
@@ -232,6 +232,11 @@ gfx::Size RenderWidgetHostViewChildFrame::GetVisibleViewportSize() const {
   // to be a main frame.  This should be cleaned up eventually.
   bool is_guest = BrowserPluginGuest::IsGuest(RenderViewHostImpl::From(host_));
   if (frame_connector_ && !is_guest) {
+    // An auto-resize set by the top-level frame overrides what would be
+    // reported by embedding RenderWidgetHostViews.
+    if (host_->delegate() && !host_->delegate()->GetAutoResizeSize().IsEmpty())
+      return host_->delegate()->GetAutoResizeSize();
+
     RenderWidgetHostView* parent_view =
         frame_connector_->GetParentRenderWidgetHostView();
     // The parent_view can be null in unit tests when using a TestWebContents.