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

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index c261287510b0cdf90960b72b25b3bcb904b82f6b..454198b33a4bd37df9acc7e65fa0a29555214fff 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -1784,7 +1784,7 @@ void Document::updateStyle(StyleRecalcChange change)
     if (change == Force) {
         m_hasNodesWithPlaceholderStyle = false;
         RefPtr<RenderStyle> documentStyle = StyleResolver::styleForDocument(*this, m_styleEngine->fontSelector());
-        StyleRecalcChange localChange = RenderStyle::compare(documentStyle.get(), renderView()->style());
+        StyleRecalcChange localChange = RenderStyle::stylePropagationDiff(documentStyle.get(), renderView()->style());
         if (localChange != NoChange)
             renderView()->setStyle(documentStyle.release());
     }