AU: Fix potential issues with premature destruction of HTTP fetchers.

download_action.h

Index: download_action.h
diff --git a/download_action.h b/download_action.h
index d0ac175f737d7c631558245addcee85a12c722f9..61067405513c7b42fa71cb8a7f05dbd398349205 100644
--- a/download_action.h
+++ b/download_action.h
@@ -88,6 +88,7 @@ class DownloadAction : public Action<DownloadAction>,
                              const char* bytes, int length);
   virtual void SeekToOffset(off_t offset);
   virtual void TransferComplete(HttpFetcher *fetcher, bool successful);
+  virtual void TransferTerminated(HttpFetcher *fetcher);
 
   DownloadActionDelegate* delegate() const { return delegate_; }
   void set_delegate(DownloadActionDelegate* delegate) {
@@ -124,6 +125,10 @@ class DownloadAction : public Action<DownloadAction>,
   // Used to find the hash of the bytes downloaded
   OmahaHashCalculator omaha_hash_calculator_;
 
+  // Used by TransferTerminated to figure if this action terminated itself or
+  // was terminated by the action processor.
+  ActionExitCode code_;
+
   // For reporting status to outsiders
   DownloadActionDelegate* delegate_;
   uint64_t bytes_received_;