Propagate viewport intersection across OOPIFs at the correct time

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/frame/RemoteFrameView.h"
 
 #include "core/dom/IntersectionObserverEntry.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/RemoteFrame.h"
@@ skipping 41 matching lines @@
     return;
 
   // Start with rect in remote frame's coordinate space. Then
   // mapToVisualRectInAncestorSpace will move it to the local root's coordinate
   // space and account for any clip from containing elements such as a
   // scrollable div. Passing nullptr as an argument to
   // mapToVisualRectInAncestorSpace causes it to be clipped to the viewport,
   // even if there are RemoteFrame ancestors in the frame tree.
   LayoutRect rect(0, 0, frame_rect_.Width(), frame_rect_.Height());
   rect.Move(remote_frame_->OwnerLayoutObject()->ContentBoxOffset());
-  if (!remote_frame_->OwnerLayoutObject()->MapToVisualRectInAncestorSpace(
-          nullptr, rect))
-    return;
-  IntRect root_visible_rect = local_root_view->VisibleContentRect();
-  IntRect viewport_intersection(rect);
-  viewport_intersection.Intersect(root_visible_rect);
-  viewport_intersection.Move(-local_root_view->ScrollOffsetInt());
+  IntRect viewport_intersection;
+  if (remote_frame_->OwnerLayoutObject()->MapToVisualRectInAncestorSpace(
+          nullptr, rect)) {
+    IntRect root_visible_rect = local_root_view->VisibleContentRect();
+    IntRect intersected_rect(rect);
+    intersected_rect.Intersect(root_visible_rect);
+    intersected_rect.Move(-local_root_view->ScrollOffsetInt());
 
-  // Translate the intersection rect from the root frame's coordinate space
-  // to the remote frame's coordinate space.
-  viewport_intersection = ConvertFromRootFrame(viewport_intersection);
+    // Translate the intersection rect from the root frame's coordinate space
+    // to the remote frame's coordinate space.
+    viewport_intersection = ConvertFromRootFrame(intersected_rect);
+  }
+
   if (viewport_intersection != last_viewport_intersection_) {
     remote_frame_->Client()->UpdateRemoteViewportIntersection(
         viewport_intersection);
   }
+
   last_viewport_intersection_ = viewport_intersection;
 }
 
 void RemoteFrameView::Dispose() {
   HTMLFrameOwnerElement* owner_element = remote_frame_->DeprecatedLocalOwner();
   // ownerElement can be null during frame swaps, because the
   // RemoteFrameView is disconnected before detachment.
   if (owner_element && owner_element->OwnedWidget() == this)
     owner_element->SetWidget(nullptr);
 }
@@ skipping 18 matching lines @@
 }
 
 void RemoteFrameView::FrameRectsChanged() {
   // Update the rect to reflect the position of the frame relative to the
   // containing local frame root. The position of the local root within
   // any remote frames, if any, is accounted for by the embedder.
   IntRect new_rect = frame_rect_;
   if (parent_)
     new_rect = parent_->ConvertToRootFrame(parent_->ContentsToFrame(new_rect));
   remote_frame_->Client()->FrameRectsChanged(new_rect);
-
-  UpdateRemoteViewportIntersection();
 }
 
 void RemoteFrameView::Hide() {
   self_visible_ = false;
   remote_frame_->Client()->VisibilityChanged(false);
 }
 
 void RemoteFrameView::Show() {
   self_visible_ = true;
   remote_frame_->Client()->VisibilityChanged(true);
@@ skipping 21 matching lines @@
 
   return parent_rect;
 }
 
 DEFINE_TRACE(RemoteFrameView) {
   visitor->Trace(remote_frame_);
   visitor->Trace(parent_);
 }
 
 }  // namespace blink