Make RenderObject::style() return a const object

Source/core/rendering/RenderTextControlSingleLine.cpp

Index: Source/core/rendering/RenderTextControlSingleLine.cpp
diff --git a/Source/core/rendering/RenderTextControlSingleLine.cpp b/Source/core/rendering/RenderTextControlSingleLine.cpp
index 130f24bb49404496653a0901e1ad166025a5475b..f0eada926c6ff5563cdb9f197efcaf0e306b9661 100644
--- a/Source/core/rendering/RenderTextControlSingleLine.cpp
+++ b/Source/core/rendering/RenderTextControlSingleLine.cpp
@@ -110,14 +110,14 @@ void RenderTextControlSingleLine::layout()
 
     // To ensure consistency between layouts, we need to reset any conditionally overriden height.
     if (innerEditorRenderer && !innerEditorRenderer->style()->logicalHeight().isAuto()) {
-        innerEditorRenderer->style()->setLogicalHeight(Length(Auto));
+        innerEditorRenderer->mutableStyleRef().setLogicalHeight(Length(Auto));
         layoutScope.setNeedsLayout(innerEditorRenderer);
         HTMLElement* placeholderElement = inputElement()->placeholderElement();
         if (RenderBox* placeholderBox = placeholderElement ? placeholderElement->renderBox() : 0)
             layoutScope.setNeedsLayout(placeholderBox);
     }
     if (viewPortRenderer && !viewPortRenderer->style()->logicalHeight().isAuto()) {
-        viewPortRenderer->style()->setLogicalHeight(Length(Auto));
+        viewPortRenderer->mutableStyleRef().setLogicalHeight(Length(Auto));
         layoutScope.setNeedsLayout(viewPortRenderer);
     }
 
@@ -135,10 +135,10 @@ void RenderTextControlSingleLine::layout()
 
         m_desiredInnerEditorLogicalHeight = desiredLogicalHeight;
 
-        innerEditorRenderer->style()->setLogicalHeight(Length(desiredLogicalHeight, Fixed));
+        innerEditorRenderer->mutableStyleRef().setLogicalHeight(Length(desiredLogicalHeight, Fixed));
         layoutScope.setNeedsLayout(innerEditorRenderer);
         if (viewPortRenderer) {
-            viewPortRenderer->style()->setLogicalHeight(Length(desiredLogicalHeight, Fixed));
+            viewPortRenderer->mutableStyleRef().setLogicalHeight(Length(desiredLogicalHeight, Fixed));
             layoutScope.setNeedsLayout(viewPortRenderer);
         }
     }
@@ -147,13 +147,14 @@ void RenderTextControlSingleLine::layout()
         containerRenderer->layoutIfNeeded();
         LayoutUnit containerLogicalHeight = containerRenderer->logicalHeight();
         if (containerLogicalHeight > logicalHeightLimit) {
-            containerRenderer->style()->setLogicalHeight(Length(logicalHeightLimit, Fixed));
+            containerRenderer->mutableStyleRef().setLogicalHeight(Length(logicalHeightLimit, Fixed));
             layoutScope.setNeedsLayout(this);
         } else if (containerRenderer->logicalHeight() < contentLogicalHeight()) {
-            containerRenderer->style()->setLogicalHeight(Length(contentLogicalHeight(), Fixed));
+            containerRenderer->mutableStyleRef().setLogicalHeight(Length(contentLogicalHeight(), Fixed));
             layoutScope.setNeedsLayout(this);
-        } else
-            containerRenderer->style()->setLogicalHeight(Length(containerLogicalHeight, Fixed));
+        } else {
+            containerRenderer->mutableStyleRef().setLogicalHeight(Length(containerLogicalHeight, Fixed));
+        }
     }
 
     // If we need another layout pass, we have changed one of children's height so we need to relayout them.
@@ -173,8 +174,8 @@ void RenderTextControlSingleLine::layout()
 
         if (innerEditorRenderer)
             innerEditorSize = innerEditorRenderer->size();
-        placeholderBox->style()->setWidth(Length(innerEditorSize.width() - placeholderBox->borderAndPaddingWidth(), Fixed));
-        placeholderBox->style()->setHeight(Length(innerEditorSize.height() - placeholderBox->borderAndPaddingHeight(), Fixed));
+        placeholderBox->mutableStyleRef().setWidth(Length(innerEditorSize.width() - placeholderBox->borderAndPaddingWidth(), Fixed));
+        placeholderBox->mutableStyleRef().setHeight(Length(innerEditorSize.height() - placeholderBox->borderAndPaddingHeight(), Fixed));
         bool neededLayout = placeholderBox->needsLayout();
         placeholderBox->layoutIfNeeded();
         LayoutPoint textOffset;
@@ -225,13 +226,13 @@ void RenderTextControlSingleLine::styleDidChange(StyleDifference diff, const Lay
     // Reset them now to avoid getting a spurious layout hint.
     Element* viewPort = editingViewPortElement();
     if (LayoutObject* viewPortRenderer = viewPort ? viewPort->renderer() : 0) {
-        viewPortRenderer->style()->setHeight(Length());
-        viewPortRenderer->style()->setWidth(Length());
+        viewPortRenderer->mutableStyle()->setHeight(Length());
+        viewPortRenderer->mutableStyle()->setWidth(Length());
     }
     Element* container = containerElement();
     if (LayoutObject* containerRenderer = container ? container->renderer() : 0) {
-        containerRenderer->style()->setHeight(Length());
-        containerRenderer->style()->setWidth(Length());
+        containerRenderer->mutableStyle()->setHeight(Length());
+        containerRenderer->mutableStyle()->setWidth(Length());
     }
     LayoutObject* innerEditorRenderer = innerEditorElement()->renderer();
     if (innerEditorRenderer && diff.needsFullLayout())