Remove DCHECK that crashes.

content/common/frame_messages.h

Index: content/common/frame_messages.h
diff --git a/content/common/frame_messages.h b/content/common/frame_messages.h
index 5e159ff90f12c86e951d288c72a587eb67e3f788..a234ee2286d5027a4f60522b3b1eb990f860b2d4 100644
--- a/content/common/frame_messages.h
+++ b/content/common/frame_messages.h
@@ -1469,11 +1469,10 @@ IPC_SYNC_MESSAGE_ROUTED4_2(FrameHostMsg_RunJavaScriptDialog,
 // Displays a dialog to confirm that the user wants to navigate away from the
 // page. Replies true if yes, and false otherwise. The reply string is ignored,
 // but is included so that we can use OnJavaScriptMessageBoxClosed.
-IPC_SYNC_MESSAGE_ROUTED2_2(FrameHostMsg_RunBeforeUnloadConfirm,
-                           GURL,           /* in - originating frame URL */
-                           bool            /* in - is a reload */,
-                           bool            /* out - success */,
-                           base::string16  /* out - This is ignored.*/)
+IPC_SYNC_MESSAGE_ROUTED1_2(FrameHostMsg_RunBeforeUnloadConfirm,
+                           bool /* in - is a reload */,
+                           bool /* out - success */,
+                           base::string16 /* out - This is ignored.*/)
 
 // Asks the browser to open the color chooser.
 IPC_MESSAGE_ROUTED3(FrameHostMsg_OpenColorChooser,