diff --git a/mozilla/layout/html/forms/src/nsGfxTextControlFrame.h b/mozilla/layout/html/forms/src/nsGfxTextControlFrame.h
index 0a4096679e0..17f26b449d4 100644
--- a/mozilla/layout/html/forms/src/nsGfxTextControlFrame.h
+++ b/mozilla/layout/html/forms/src/nsGfxTextControlFrame.h
@@ -508,7 +508,8 @@ protected:
   PRBool mNeedsStyleInit;
   PRBool mDummyInitialized; //DUMMY
   nsIPresContext *mFramePresContext; // not ref counted
-  nsString* mCachedState;
+  nsString* mCachedState; // this is used for caching changed between frame creation
+                          // and full initialization
 };
 
 #endif