Fix a crash when delegate_ goes away in ReadStream...

chrome_frame/urlmon_url_request.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome_frame/urlmon_url_request.h"
 
 #include <wininet.h>
 #include <urlmon.h>
 
 #include "base/logging.h"
@@ skipping 203 matching lines @@
       // response end notification to chrome.
       if (hr == S_FALSE)
         pending_data_.Release();
     }
 
     bytes_copied = read_data.length();
 
     if (bytes_copied) {
       ++calling_delegate_;
       DCHECK_NE(id(), -1);
-      delegate_->OnReadComplete(id(), read_data);
+      // The delegate can go away in the middle of ReadStream
+      if (delegate_)
+        delegate_->OnReadComplete(id(), read_data);
       --calling_delegate_;
     }
   } else {
     DLOG(ERROR) << __FUNCTION__ << me() << "no delegate";
   }
 
   return bytes_copied;
 }
 
 STDMETHODIMP UrlmonUrlRequest::OnStartBinding(DWORD reserved,
@@ skipping 926 matching lines @@
       privacy_info_.privacy_records[UTF8ToWide(url)];
 
   privacy_entry.flags |= flags;
   privacy_entry.policy_ref = UTF8ToWide(policy_ref);
 
   if (fire_privacy_event && IsWindow(notification_window_)) {
     PostMessage(notification_window_, WM_FIRE_PRIVACY_CHANGE_NOTIFICATION, 1,
                 0);
   }
 }