Rename RenderStyle::diff and RenderStyle::compare to better names

Source/core/rendering/style/RenderStyle.h

Index: Source/core/rendering/style/RenderStyle.h
diff --git a/Source/core/rendering/style/RenderStyle.h b/Source/core/rendering/style/RenderStyle.h
index 3cbdf5073e1f503a45420bde7718bc1239b66552..39789397a56aaf54c9aeb97b0b1bb7a5f5c1c91d 100644
--- a/Source/core/rendering/style/RenderStyle.h
+++ b/Source/core/rendering/style/RenderStyle.h
@@ -356,7 +356,11 @@ public:
     static PassRefPtr<RenderStyle> createAnonymousStyleWithDisplay(const RenderStyle* parentStyle, EDisplay);
     static PassRefPtr<RenderStyle> clone(const RenderStyle*);
 
-    static StyleRecalcChange compare(const RenderStyle* oldStyle, const RenderStyle* newStyle);
+    // Computes how the style change should be propagated down the tree.
+    static StyleRecalcChange stylePropagationDiff(const RenderStyle* oldStyle, const RenderStyle* newStyle);
+
+    // Computes how much visual invalidation the style change causes: layout, repaint or recomposite.
+    StyleDifference visualInvalidationDiff(const RenderStyle*, unsigned& changedContextSensitiveProperties) const;
 
     enum IsAtShadowBoundary {
         AtShadowBoundary,
@@ -1494,8 +1498,6 @@ public:
     bool inheritedNotEqual(const RenderStyle*) const;
     bool inheritedDataShared(const RenderStyle*) const;
 
-    StyleDifference diff(const RenderStyle*, unsigned& changedContextSensitiveProperties) const;
-
     bool isDisplayReplacedType() const { return isDisplayReplacedType(display()); }
     bool isDisplayInlineType() const { return isDisplayInlineType(display()); }
     bool isOriginalDisplayInlineType() const { return isDisplayInlineType(originalDisplay()); }