Make cancel remove cancelled download from active queues at time of cancel.

content/browser/download/download_item.h

Index: content/browser/download/download_item.h
diff --git a/content/browser/download/download_item.h b/content/browser/download/download_item.h
index 07c43fec9bfd2cb1a94dffceb6402247e0c10531..7a81aa0430ef5cbd7434a1358cf8888119dd16d3 100644
--- a/content/browser/download/download_item.h
+++ b/content/browser/download/download_item.h
@@ -157,16 +157,11 @@ class CONTENT_EXPORT DownloadItem {
   // Received a new chunk of data
   void Update(int64 bytes_so_far);
 
-  // Cancel the download operation. We need to distinguish between cancels at
-  // exit (DownloadManager destructor) from user interface initiated cancels
-  // because at exit, the history system may not exist, and any updates to it
-  // require AddRef'ing the DownloadManager in the destructor which results in
-  // a DCHECK failure. Set 'update_history' to false when canceling from at
-  // exit to prevent this crash. This may result in a difference between the
-  // downloaded file's size on disk, and what the history system's last record
-  // of it is. At worst, we'll end up re-downloading a small portion of the file
-  // when resuming a download (assuming the server supports byte ranges).
-  void Cancel(bool update_history);
+  // Cancel the download operation.  This may be called at any time; if
+  // it is called before all download attributes have been finalized and
+  // the download entered into the history, it will remove the download from
+  // the system.
+  void Cancel();
 
   // Called by external code (SavePackage) using the DownloadItem interface
   // to display progress when the DownloadItem should be considered complete.
@@ -182,10 +177,14 @@ class CONTENT_EXPORT DownloadItem {
   // Called when the downloaded file is removed.
   void OnDownloadedFileRemoved();
 
-  // Download operation had an error.
-  // |size| is the amount of data received at interruption.
-  // |error| is the network error code that the operation received.
-  void Interrupted(int64 size, net::Error error);
+  // Download operation had an error; call to interrupt the processing.
+  // Note that if the download attributes haven't yet been finalized and
+  // the download entered into the history (which implies that it hasn't
+  // yet been made visible in the UI), this call will remove the
+  // download from the system.
+  // |size| is the amount of data received so far, and |net_error| is the
+  // error code that the operation received.
+  void Interrupt(int64 size, net::Error net_error);
 
   // Deletes the file from disk and removes the download from the views and
   // history.  |user| should be true if this is the result of the user clicking
@@ -357,7 +356,8 @@ class CONTENT_EXPORT DownloadItem {
   void StartProgressTimer();
   void StopProgressTimer();
 
-  // Call to transition state; all state transitions should go through this.
+  // Does the actual work of transition state; all state
+  // transitions should go through this.
   void TransitionTo(DownloadState new_state);
 
   // Called when safety_state_ should be recomputed from is_dangerous_file