Ensure paint properties are rebuilt on window resizes

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

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 633 matching lines @@
   ScrollableArea::contentsResized();
 
   Page* page = frame().page();
   if (!page)
     return;
 
   updateParentScrollableAreaSet();
 
   page->chromeClient().contentsSizeChanged(m_frame.get(), size);
   frame().loader().restoreScrollPositionAndViewState();
-
-  if (!RuntimeEnabledFeatures::rootLayerScrollingEnabled()) {
-    // The presence of overflow depends on the contents size. The scroll
-    // properties can change depending on whether overflow scrolling occurs.
-    setNeedsPaintPropertyUpdate();
-  }
 }
 
 void FrameView::adjustViewSize() {
   if (m_suppressAdjustViewSize)
     return;
 
   LayoutViewItem layoutViewItem = this->layoutViewItem();
   if (layoutViewItem.isNull())
     return;
 
@@ skipping 2891 matching lines @@
     return;
   page->chromeClient().setCursor(cursor, m_frame);
 }
 
 void FrameView::frameRectsChanged() {
   TRACE_EVENT0("blink", "FrameView::frameRectsChanged");
   if (layoutSizeFixedToFrameSize())
     setLayoutSizeInternal(frameRect().size());
 
   setNeedsUpdateViewportIntersection();
+  if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {

[Xianzhu, 2016/11/27 18:00:04]

slimmingPaintInvalidationEnabled?

[pdr., 2016/11/28 03:15:05]

I've been using RuntimeEnabledFeatures::slimmingPaintV2Enabled for the paint
property tree invalidation work so far, but that may have been a mistake. Should
it be behind RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled? If so,
which parts should be slimmingPaintInvalidationEnabled vs
slimmingPaintV2Enabled?

[Xianzhu, 2016/11/28 17:56:00]

Oh, I didn't notice this before. We should use slimmingPaintInvalidationEnabled
where it's guarding property tree building.

+    // The overflow clip property depends on the frame rect.
+    setNeedsPaintPropertyUpdate();
+  }
+
   for (const auto& child : m_children)
     child->frameRectsChanged();
 }
 
 void FrameView::setLayoutSizeInternal(const IntSize& size) {
   if (m_layoutSize == size)
     return;
 
   m_layoutSize = size;
   contentsResized();
@@ skipping 1066 matching lines @@
   DCHECK(m_frame->isMainFrame());
   return m_initialViewportSize.width();
 }
 
 int FrameView::initialViewportHeight() const {
   DCHECK(m_frame->isMainFrame());
   return m_initialViewportSize.height();
 }
 
 }  // namespace blink