Implement incremental paint property tree rebuilding

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 3359 matching lines @@
 }
 
 void FrameView::frameRectsChanged() {
   TRACE_EVENT0("blink", "FrameView::frameRectsChanged");
   if (layoutSizeFixedToFrameSize())
     setLayoutSizeInternal(frameRect().size());
 
   setNeedsUpdateViewportIntersection();
   for (const auto& child : m_children)
     child->frameRectsChanged();
+
+  setPaintPropertiesInvalid();

[chrishtr, 2016/10/21 22:03:09]

Add a brief comment explaining which property tree nodes are invalidated by
changed frame rect.

[pdr., 2016/10/26 03:10:48]

Done

 }
 
 void FrameView::setLayoutSizeInternal(const IntSize& size) {
   if (m_layoutSize == size)
     return;
 
   m_layoutSize = size;
   contentsResized();
 }
 
@@ skipping 218 matching lines @@
   }
 
   if (scrollType != AnchoringScroll)
     clearScrollAnchor();
 }
 
 void FrameView::didChangeScrollOffset() {
   frame().loader().client()->didChangeScrollOffset();
   if (frame().isMainFrame())
     frame().host()->chromeClient().mainFrameScrollOffsetChanged();
+  setPaintPropertiesInvalid();

[chrishtr, 2016/10/21 22:03:09]

Add a brief comment explaining which property tree nodes are invalidated by
changed scroll.

(it's the scroll offset one right? and it only needs its matrix contents
adjusted?)

[pdr., 2016/10/26 03:10:48]

Done. I tightened these invalidations up a bit as well (only in scroll offset
and contents size changed functions now).

 }
 
 void FrameView::clearScrollAnchor() {
   if (!RuntimeEnabledFeatures::scrollAnchoringEnabled())
     return;
   m_scrollAnchor.clear();
 }
 
 bool FrameView::hasOverlayScrollbars() const {
   return (m_horizontalScrollbar &&
@@ skipping 861 matching lines @@
   DCHECK(m_frame->isMainFrame());
   return m_initialViewportSize.width();
 }
 
 int FrameView::initialViewportHeight() const {
   DCHECK(m_frame->isMainFrame());
   return m_initialViewportSize.height();
 }
 
 }  // namespace blink