Rename StyleSheetCollections to StyleEngine.

Source/core/dom/DocumentStyleSheetCollection.h

Index: Source/core/dom/DocumentStyleSheetCollection.h
diff --git a/Source/core/dom/DocumentStyleSheetCollection.h b/Source/core/dom/DocumentStyleSheetCollection.h
index 9f035f00344d6d6f58020f7383213178f919082b..1a039fbdb92de4e205b8f9a320de3ee4bfcce297 100644
--- a/Source/core/dom/DocumentStyleSheetCollection.h
+++ b/Source/core/dom/DocumentStyleSheetCollection.h
@@ -35,7 +35,7 @@ namespace WebCore {
 class CSSStyleSheet;
 class StyleSheet;
 class StyleSheetCollection;
-class StyleSheetCollections;
+class StyleEngine;
 class TreeScope;
 
 class DocumentStyleSheetCollection FINAL : public StyleSheetCollection {
@@ -43,10 +43,10 @@ class DocumentStyleSheetCollection FINAL : public StyleSheetCollection {
 public:
     explicit DocumentStyleSheetCollection(TreeScope&);
 
-    bool updateActiveStyleSheets(StyleSheetCollections*, StyleResolverUpdateMode);
+    bool updateActiveStyleSheets(StyleEngine*, StyleResolverUpdateMode);
 
 private:
-    void collectStyleSheets(StyleSheetCollections*, Vector<RefPtr<StyleSheet> >& styleSheets, Vector<RefPtr<CSSStyleSheet> >& activeSheets);
+    void collectStyleSheets(StyleEngine*, Vector<RefPtr<StyleSheet> >& styleSheets, Vector<RefPtr<CSSStyleSheet> >& activeSheets);
 };
 
 }