Fix a potential crash by clearing callback_ before running it....

webkit/glue/resource_fetcher.h

Index: webkit/glue/resource_fetcher.h
===================================================================
--- webkit/glue/resource_fetcher.h	(revision 71961)
+++ webkit/glue/resource_fetcher.h	(working copy)
@@ -75,9 +75,6 @@
   // URL we're fetching
   GURL url_;
 
-  // Callback when we're done
-  scoped_ptr<Callback> callback_;
-
   // A copy of the original resource response
   WebKit::WebURLResponse response_;
 
@@ -88,6 +85,12 @@
   // Start the actual download.
   void Start(WebKit::WebFrame* frame);
 
+  void RunCallback(const WebKit::WebURLResponse& response,
+                   const std::string& data);
+
+  // Callback when we're done
+  scoped_ptr<Callback> callback_;
+
   // Buffer to hold the content from the server.
   std::string data_;