Revert "Improve origin-clean algorithm"

This reverts commit e69b3f567c4b8957cc09ba4359e84939f77781c5.

dom/canvas/CanvasUtils.h

@@ -11,7 +11,6 @@
 #include "mozilla/dom/ToJSValue.h"
 #include "jsapi.h"
 #include "mozilla/FloatingPoint.h"
-#include "nsLayoutUtils.h"
 
 class nsIPrincipal;
 
@@ -157,10 +156,6 @@ DashArrayToJSVal(nsTArray<T>& dashes,
     }
 }
 
-// returns true if write-only mode must used for this principal based on
-// the incumbent global.
-bool CheckWriteOnlySecurity(bool aCORSUsed, nsIPrincipal* aPrincipal);
-
 } // namespace CanvasUtils
 } // namespace mozilla