Don't forget to free the callbacks!

webkit/glue/resource_fetcher.cc

Index: webkit/glue/resource_fetcher.cc
===================================================================
--- webkit/glue/resource_fetcher.cc	(revision 20031)
+++ webkit/glue/resource_fetcher.cc	(working copy)
@@ -84,8 +84,10 @@
   DCHECK(!completed_);
   completed_ = true;
 
-  if (callback_)
+  if (callback_.get()) {
     callback_->Run(response_, data_);
+    callback_.reset();
+  }
 }
 
 void ResourceFetcher::didFail(WebURLLoader* loader, const WebURLError& error) {
@@ -93,8 +95,10 @@
   completed_ = true;
 
   // Go ahead and tell our delegate that we're done.
-  if (callback_)
+  if (callback_.get()) {
     callback_->Run(WebURLResponse(), std::string());
+    callback_.reset();
+  }
 }
 
 /////////////////////////////////////////////////////////////////////////////