Remove relayout due to scrollbars taking up width

sky/engine/core/rendering/RenderLayerScrollableArea.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 52 matching lines @@
 #include "sky/engine/platform/scroll/ScrollAnimator.h"
 #include "sky/engine/platform/scroll/Scrollbar.h"
 #include "sky/engine/public/platform/Platform.h"
 
 namespace blink {
 
 RenderLayerScrollableArea::RenderLayerScrollableArea(RenderLayer& layer)
     : m_layer(layer)
     , m_scrollsOverflow(false)
     , m_scrollDimensionsDirty(true)
-    , m_inOverflowRelayout(false)
     , m_nextTopmostScrollChild(0)
     , m_topmostScrollChild(0)
     , m_needsCompositedScrolling(false)
 {
     ScrollableArea::setConstrainsScrollingToContentEdge(false);
 
     Node* node = box().node();
     if (node && node->isElementNode()) {
         // We save and restore only the scrollOffset as the other scroll values are recalculated.
         Element* element = toElement(node);
@@ skipping 317 matching lines @@
     IntSize clampedScrollOffset = clampScrollOffset(adjustedScrollOffset());
     if (clampedScrollOffset != adjustedScrollOffset())
         scrollToOffset(clampedScrollOffset);
 
     if (originalScrollOffset != adjustedScrollOffset())
         scrollToOffsetWithoutAnimation(-scrollOrigin() + adjustedScrollOffset());
 
     bool hasHorizontalOverflow = this->hasHorizontalOverflow();
     bool hasVerticalOverflow = this->hasVerticalOverflow();
 
-    {
-        // Hits in compositing/overflow/automatically-opt-into-composited-scrolling-after-style-change.html.
-        DisableCompositingQueryAsserts disabler;
-
-        // overflow:scroll should just enable/disable.
-        if (box().style()->overflowX() == OSCROLL)
-            horizontalScrollbar()->setEnabled(hasHorizontalOverflow);
-        if (box().style()->overflowY() == OSCROLL)
-            verticalScrollbar()->setEnabled(hasVerticalOverflow);
-    }
+    // overflow:scroll should just enable/disable.
+    if (box().style()->overflowX() == OSCROLL)
+        horizontalScrollbar()->setEnabled(hasHorizontalOverflow);
+    if (box().style()->overflowY() == OSCROLL)
+        verticalScrollbar()->setEnabled(hasVerticalOverflow);
 
     // overflow:auto may need to lay out again if scrollbars got added/removed.
-    bool autoHorizontalScrollBarChanged = box().hasAutoHorizontalScrollbar() && (hasHorizontalScrollbar() != hasHorizontalOverflow);
-    bool autoVerticalScrollBarChanged = box().hasAutoVerticalScrollbar() && (hasVerticalScrollbar() != hasVerticalOverflow);
+    if (box().hasAutoHorizontalScrollbar())
+        setHasHorizontalScrollbar(hasHorizontalOverflow);

[ojan, 2014/12/10 03:40:38]

These already have the hasHorizontalScrollbar() != hasHorizontalOverflow check,
so we don't need the autoHorizontalScrollBarChanged check anymore.

+    if (box().hasAutoVerticalScrollbar())
+        setHasVerticalScrollbar(hasVerticalOverflow);
 
-    if (autoHorizontalScrollBarChanged || autoVerticalScrollBarChanged) {
-        if (box().hasAutoHorizontalScrollbar())
-            setHasHorizontalScrollbar(hasHorizontalOverflow);
-        if (box().hasAutoVerticalScrollbar())
-            setHasVerticalScrollbar(hasVerticalOverflow);
-
-        layer()->updateSelfPaintingLayer();
-
-        if (box().style()->overflowX() == OAUTO || box().style()->overflowY() == OAUTO) {
-            if (!m_inOverflowRelayout) {
-                // Our proprietary overflow: overlay value doesn't trigger a layout.
-                m_inOverflowRelayout = true;
-                SubtreeLayoutScope layoutScope(box());
-                layoutScope.setNeedsLayout(&box());
-                if (box().isRenderBlock()) {
-                    RenderBlock& block = toRenderBlock(box());
-                    block.scrollbarsChanged(autoHorizontalScrollBarChanged, autoVerticalScrollBarChanged);
-                    block.layoutBlock(true);
-                } else {
-                    box().layout();
-                }
-                m_inOverflowRelayout = false;
-            }
-        }
+    // Set up the range (and page step/line step).
+    if (Scrollbar* horizontalScrollbar = this->horizontalScrollbar()) {
+        int clientWidth = box().pixelSnappedClientWidth();
+        horizontalScrollbar->setProportion(clientWidth, overflowRect().width());
     }
-
-    {
-        // Hits in compositing/overflow/automatically-opt-into-composited-scrolling-after-style-change.html.
-        DisableCompositingQueryAsserts disabler;
-
-        // Set up the range (and page step/line step).
-        if (Scrollbar* horizontalScrollbar = this->horizontalScrollbar()) {
-            int clientWidth = box().pixelSnappedClientWidth();
-            horizontalScrollbar->setProportion(clientWidth, overflowRect().width());
-        }
-        if (Scrollbar* verticalScrollbar = this->verticalScrollbar()) {
-            int clientHeight = box().pixelSnappedClientHeight();
-            verticalScrollbar->setProportion(clientHeight, overflowRect().height());
-        }
+    if (Scrollbar* verticalScrollbar = this->verticalScrollbar()) {
+        int clientHeight = box().pixelSnappedClientHeight();
+        verticalScrollbar->setProportion(clientHeight, overflowRect().height());
     }
 
     bool hasOverflow = hasScrollableHorizontalOverflow() || hasScrollableVerticalOverflow();
     updateScrollableAreaSet(hasOverflow);
 
     if (hasOverflow) {
-        DisableCompositingQueryAsserts disabler;
         positionOverflowControls(IntSize());
     }
 }
 
 bool RenderLayerScrollableArea::hasHorizontalOverflow() const
 {
     ASSERT(!m_scrollDimensionsDirty);
 
     return pixelSnappedScrollWidth() > box().pixelSnappedClientWidth();
 }
@@ skipping 174 matching lines @@
     scrollbar->disconnectFromScrollableArea();
     scrollbar = nullptr;
 }
 
 void RenderLayerScrollableArea::setHasHorizontalScrollbar(bool hasScrollbar)
 {
     if (hasScrollbar == hasHorizontalScrollbar())
         return;
 
     if (hasScrollbar) {
-        // This doesn't hit in any tests, but since the equivalent code in setHasVerticalScrollbar
-        // does, presumably this code does as well.
-        DisableCompositingQueryAsserts disabler;
         m_hBar = createScrollbar(HorizontalScrollbar);
     } else {
         destroyScrollbar(HorizontalScrollbar);
     }
 }
 
 void RenderLayerScrollableArea::setHasVerticalScrollbar(bool hasScrollbar)
 {
     if (hasScrollbar == hasVerticalScrollbar())
         return;
 
     if (hasScrollbar) {
-        // Hits in compositing/overflow/automatically-opt-into-composited-scrolling-after-style-change.html
-        DisableCompositingQueryAsserts disabler;
         m_vBar = createScrollbar(VerticalScrollbar);
     } else {
         destroyScrollbar(VerticalScrollbar);
     }
 }
 
 void RenderLayerScrollableArea::positionOverflowControls(const IntSize& offsetFromRoot)
 {
     if (!hasScrollbar())
         return;
@@ skipping 112 matching lines @@
 void RenderLayerScrollableArea::setTopmostScrollChild(RenderLayer* scrollChild)
 {
     // We only want to track the topmost scroll child for scrollable areas with
     // overlay scrollbars.
     if (!hasOverlayScrollbars())
         return;
     m_nextTopmostScrollChild = scrollChild;
 }
 
 } // namespace blink