Make RenderObject::style() return a const object

Source/core/rendering/RenderBlock.cpp

Index: Source/core/rendering/RenderBlock.cpp
diff --git a/Source/core/rendering/RenderBlock.cpp b/Source/core/rendering/RenderBlock.cpp
index e4db4b8cda56117b561922587fb7436335018bf9..89b99eb5f6531ca610369a506ae7d78e776d07bb 100644
--- a/Source/core/rendering/RenderBlock.cpp
+++ b/Source/core/rendering/RenderBlock.cpp
@@ -197,7 +197,7 @@ static void appendLayers(Vector<ImageResource*>& images, const FillLayer& styleL
         appendImageIfNotNull(images, layer->image());
 }
 
-static void appendImagesFromStyle(Vector<ImageResource*>& images, RenderStyle& blockStyle)
+static void appendImagesFromStyle(Vector<ImageResource*>& images, const RenderStyle& blockStyle)
 {
     appendLayers(images, blockStyle.backgroundLayers());
     appendLayers(images, blockStyle.maskLayers());
@@ -293,7 +293,7 @@ void RenderBlock::willBeDestroyed()
 
 void RenderBlock::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
 {
-    RenderStyle* oldStyle = style();
+    const RenderStyle* oldStyle = style();
 
     setReplaced(newStyle.isDisplayInlineType());
 
@@ -346,7 +346,7 @@ void RenderBlock::styleDidChange(StyleDifference diff, const RenderStyle* oldSty
     if (isFloatingOrOutOfFlowPositioned() && oldStyle && !oldStyle->isFloating() && !oldStyle->hasOutOfFlowPosition() && parent() && parent()->isRenderBlockFlow())
         toRenderBlock(parent())->removeAnonymousWrappersIfRequired();
 
-    RenderStyle* newStyle = style();
+    RenderStyle* newStyle = deprecatedMutableStyle();
 
     if (!isAnonymousBlock()) {
         // Ensure that all of our continuation blocks pick up the new style.
@@ -591,7 +591,7 @@ RenderBlock* RenderBlock::clone() const
     else {
         RenderObject* cloneRenderer = toElement(node())->createRenderer(style());
         cloneBlock = toRenderBlock(cloneRenderer);
-        cloneBlock->setStyle(style());
+        cloneBlock->setStyle(deprecatedMutableStyle());
 
         // This takes care of setting the right value of childrenInline in case
         // generated content is added to cloneBlock and 'this' does not have
@@ -2982,7 +2982,7 @@ void RenderBlock::computePreferredLogicalWidths()
 
     // FIXME: The isFixed() calls here should probably be checking for isSpecified since you
     // should be able to use percentage, calc or viewport relative values for width.
-    RenderStyle* styleToUse = style();
+    const RenderStyle* styleToUse = style();
     if (!isTableCell() && styleToUse->logicalWidth().isFixed() && styleToUse->logicalWidth().value() >= 0
         && !(isDeprecatedFlexItem() && !styleToUse->logicalWidth().intValue()))
         m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = adjustContentBoxLogicalWidthForBoxSizing(styleToUse->logicalWidth().value());
@@ -3039,7 +3039,7 @@ void RenderBlock::adjustIntrinsicLogicalWidthsForColumns(LayoutUnit& minLogicalW
 
 void RenderBlock::computeBlockPreferredLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
 {
-    RenderStyle* styleToUse = style();
+    const RenderStyle* styleToUse = style();
     bool nowrap = styleToUse->whiteSpace() == NOWRAP;
 
     RenderObject* child = firstChild();
@@ -3053,7 +3053,7 @@ void RenderBlock::computeBlockPreferredLogicalWidths(LayoutUnit& minLogicalWidth
             continue;
         }
 
-        RefPtr<RenderStyle> childStyle = child->style();
+        const RenderStyle* childStyle = child->style();
         if (child->isFloating() || (child->isBox() && toRenderBox(child)->avoidsFloats())) {
             LayoutUnit floatTotalWidth = floatLeftWidth + floatRightWidth;
             if (childStyle->clear() & CLEFT) {
@@ -3160,7 +3160,7 @@ LayoutUnit RenderBlock::lineHeight(bool firstLine, LineDirectionMode direction,
     if (isReplaced() && linePositionMode == PositionOnContainingLine)
         return RenderBox::lineHeight(firstLine, direction, linePositionMode);
 
-    RenderStyle* s = style(firstLine && document().styleEngine()->usesFirstLineRules());
+    const RenderStyle* s = style(firstLine && document().styleEngine()->usesFirstLineRules());
     return s->computedLineHeight();
 }
 
@@ -3788,7 +3788,7 @@ RenderBlock* RenderBlock::createAnonymousWithParentRendererAndDisplay(const Rend
 RenderBlockFlow* RenderBlock::createAnonymousColumnsWithParentRenderer(const RenderObject* parent)
 {
     RefPtr<RenderStyle> newStyle = RenderStyle::createAnonymousStyleWithDisplay(parent->style(), BLOCK);
-    newStyle->inheritColumnPropertiesFrom(parent->style());
+    newStyle->inheritColumnPropertiesFrom(*parent->style());
 
     RenderBlockFlow* newBox = RenderBlockFlow::createAnonymous(&parent->document());
     parent->updateAnonymousChildStyle(newBox, newStyle.get());