Blink changes to record interest rects for http://w3c.github.io/frame-timing/

Source/core/rendering/RenderView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 315 matching lines @@
     // short-circuit on full-paint invalidation.
     LayoutRect dirtyRect = viewRect();
     if (doingFullPaintInvalidation() && !dirtyRect.isEmpty()) {
         const LayoutLayerModelObject* paintInvalidationContainer = &paintInvalidationState.paintInvalidationContainer();
         Layer::mapRectToPaintInvalidationBacking(this, paintInvalidationContainer, dirtyRect, &paintInvalidationState);
         invalidatePaintUsingContainer(paintInvalidationContainer, dirtyRect, PaintInvalidationFull);
     }
     RenderBlock::invalidateTreeIfNeeded(paintInvalidationState);
 }
 
+LayoutRect RenderView::rectForPaintInvalidation(const LayoutRect* paintInvalidationRectPtr) const

[enne (OOO), 2015/02/10 00:17:49]

I see your comment about this existing before and then being removed, but I
think you should investigate where it went.  I would worry about this function
becoming invisibly stale over time as paint code changes, so it'd be better if
you could reuse real functionality elsewhere rather than having this one-off.

[MikeB, 2015/03/18 21:18:34]

I updated this to be more in-line with using properties of LayoutView and not a
dedicated member function, please take a look at WebViewImpl.cpp for details.

+{
+    LayoutRect paintInvalidationRect =
+        paintInvalidationRectPtr ? *paintInvalidationRectPtr : viewRect();
+    Element* owner = document().ownerElement();
+    if (document().printing() || !m_frameView
+        || layer()->compositingState() == PaintsIntoOwnBacking || !owner)
+        return paintInvalidationRect;
+    if (RenderBox* obj = owner->renderBox()) {
+        // Intersect the viewport with the paint invalidation rect.
+        LayoutRect viewRectangle = viewRect();
+        LayoutRect rectToInvalidate = intersection(paintInvalidationRect, viewRectangle);
+
+        // Adjust for scroll offset of the view.
+        rectToInvalidate.moveBy(-viewRectangle.location());
+
+        // Adjust for frame border.
+        rectToInvalidate.moveBy(obj->contentBoxRect().location());
+        return rectToInvalidate;
+    }
+    return paintInvalidationRect;
+}
+
 void RenderView::invalidatePaintForRectangle(const LayoutRect& paintInvalidationRect, PaintInvalidationReason invalidationReason) const
 {
     ASSERT(!paintInvalidationRect.isEmpty());
 
     if (document().printing() || !m_frameView)
         return;
 
     ASSERT(layer()->compositingState() == PaintsIntoOwnBacking || !frame()->ownerRenderer());
 
     if (layer()->compositingState() == PaintsIntoOwnBacking) {
@@ skipping 635 matching lines @@
 }
 
 void RenderView::invalidateDisplayItemClients(DisplayItemList* displayItemList) const
 {
     RenderBlockFlow::invalidateDisplayItemClients(displayItemList);
     if (m_frameView)
         displayItemList->invalidate(m_frameView->displayItemClient());
 }
 
 } // namespace blink