Initial scroll-blocks-on compositor integration

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 1671 matching lines @@
         // Visible overflow on the viewport is meaningless, and the spec says to treat it as 'auto':
         if (overflowX == OVISIBLE)
             overflowX = OAUTO;
         if (overflowY == OVISIBLE)
             overflowY = OAUTO;
         // Column-gap is (ab)used by the current paged overflow implementation (in lack of other
         // ways to specify gaps between pages), so we have to propagate it too.
         columnGap = overflowStyle->columnGap();
     }
 
+    WebScrollBlocksOn scrollBlocksOn = documentElementStyle->scrollBlocksOn();
+
     RefPtr<RenderStyle> documentStyle = renderView()->style();
     if (documentStyle->writingMode() != rootWritingMode
         || documentStyle->direction() != rootDirection
         || documentStyle->overflowX() != overflowX
         || documentStyle->overflowY() != overflowY
-        || documentStyle->columnGap() != columnGap) {
+        || documentStyle->columnGap() != columnGap
+        || documentStyle->scrollBlocksOn() != scrollBlocksOn) {
         RefPtr<RenderStyle> newStyle = RenderStyle::clone(documentStyle.get());
         newStyle->setWritingMode(rootWritingMode);
         newStyle->setDirection(rootDirection);
         newStyle->setColumnGap(columnGap);
         newStyle->setOverflowX(overflowX);
         newStyle->setOverflowY(overflowY);
+        newStyle->setScrollBlocksOn(scrollBlocksOn);
         renderView()->setStyle(newStyle);
         setupFontBuilder(newStyle.get());
     }
 
     if (body) {
         if (RenderStyle* style = body->renderStyle()) {
             if (style->direction() != rootDirection || style->writingMode() != rootWritingMode)
                 body->setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::WritingModeChange));
         }
     }
@@ skipping 4044 matching lines @@
 #ifndef NDEBUG
 using namespace blink;
 void showLiveDocumentInstances()
 {
     WeakDocumentSet& set = liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (Document* document : set)
         fprintf(stderr, "- Document %p URL: %s\n", document, document->url().string().utf8().data());
 }
 #endif