Rename StyleSheetCollections to StyleEngine.

Source/core/rendering/RenderObject.h

Index: Source/core/rendering/RenderObject.h
diff --git a/Source/core/rendering/RenderObject.h b/Source/core/rendering/RenderObject.h
index a29eaafdad95ca63e27a630095b3e412a9bd4d3f..bb46ee6db760449b8c49226a553058ec6919e526 100644
--- a/Source/core/rendering/RenderObject.h
+++ b/Source/core/rendering/RenderObject.h
@@ -28,7 +28,7 @@
 
 #include "core/dom/Element.h"
 #include "core/dom/Position.h"
-#include "core/dom/StyleSheetCollections.h"
+#include "core/dom/StyleEngine.h"
 #include "core/fetch/ImageResourceClient.h"
 #include "core/platform/graphics/FloatQuad.h"
 #include "core/platform/graphics/LayoutRect.h"
@@ -774,7 +774,7 @@ public:
     virtual LayoutUnit maxPreferredLogicalWidth() const { return 0; }
 
     RenderStyle* style() const { return m_style.get(); }
-    RenderStyle* firstLineStyle() const { return document().styleSheetCollections()->usesFirstLineRules() ? cachedFirstLineStyle() : style(); }
+    RenderStyle* firstLineStyle() const { return document().styleEngine()->usesFirstLineRules() ? cachedFirstLineStyle() : style(); }
     RenderStyle* style(bool firstLine) const { return firstLine ? firstLineStyle() : style(); }
 
     inline Color resolveColor(const RenderStyle* styleToUse, int colorProperty) const