Return reference from styleEngine() accessor.

Source/core/page/InjectedStyleSheets.cpp

Index: Source/core/page/InjectedStyleSheets.cpp
diff --git a/Source/core/page/InjectedStyleSheets.cpp b/Source/core/page/InjectedStyleSheets.cpp
index 7545da28c7193e5c467c4c22166311ffb8aa2f81..b56078ed7615449ffb46bcc2b8f5f525b10113d3 100644
--- a/Source/core/page/InjectedStyleSheets.cpp
+++ b/Source/core/page/InjectedStyleSheets.cpp
@@ -55,7 +55,7 @@ void InjectedStyleSheets::invalidateInjectedStyleSheetCacheInAllFrames()
     for (const Page* page : pages) {
         for (Frame* frame = page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
             if (frame->isLocalFrame())
-                toLocalFrame(frame)->document()->styleEngine()->invalidateInjectedStyleSheetCache();
+                toLocalFrame(frame)->document()->styleEngine().invalidateInjectedStyleSheetCache();
         }
     }
 }