Update nested OOPIF's screen rects when parent is repositioned in page.

content/browser/frame_host/cross_process_frame_connector.cc

Index: content/browser/frame_host/cross_process_frame_connector.cc
diff --git a/content/browser/frame_host/cross_process_frame_connector.cc b/content/browser/frame_host/cross_process_frame_connector.cc
index 649f4a2b8c61856c9dd165fa843fcd04e8e8c2c0..c5ac363d62764c4d79ad17db75e51cf4bebfdfe0 100644
--- a/content/browser/frame_host/cross_process_frame_connector.cc
+++ b/content/browser/frame_host/cross_process_frame_connector.cc
@@ -247,9 +247,26 @@ void CrossProcessFrameConnector::SetDeviceScaleFactor(float scale_factor) {
 }
 
 void CrossProcessFrameConnector::SetRect(const gfx::Rect& frame_rect) {
+  gfx::Rect old_rect = child_frame_rect_;
   child_frame_rect_ = frame_rect;
-  if (view_)
+  if (view_) {
     view_->SetBounds(frame_rect);
+
+    // Out-of-process iframes nested underneath this one implicitly have their
+    // view rects changed when their ancestor is repositioned, and therefore
+    // need to have their screen rects updated.
+    FrameTreeNode* proxy_node =
+        frame_proxy_in_parent_renderer_->frame_tree_node();
+    if (old_rect.x() != child_frame_rect_.x() ||
+        old_rect.y() != child_frame_rect_.y()) {
+      for (FrameTreeNode* node :
+           proxy_node->frame_tree()->SubtreeNodes(proxy_node)) {
+        if (node != proxy_node &&

[nasko, 2016/03/22 13:56:54]

nit: Why not add a SubtreeNodes() call that takes a "node_to_skip", similar to
existing ones and avoid this check?

[kenrb, 2016/03/22 15:40:20]

The NodesExcept code in frame_tree.cc excludes an entire subtree, with that node
as the root, which doesn't really work here. It appears to only be used in
testing so far, in any case.

+            node->current_frame_host()->GetRenderWidgetHost())
+          node->current_frame_host()->GetRenderWidgetHost()->SendScreenRects();
+      }
+    }
+  }
 }
 
 RenderWidgetHostViewBase*