Isolate initiation counts for downloads to their own histograms and improve

chrome/browser/download/download_throttling_resource_handler.cc

 // Copyright (c) 2012 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/browser/download/download_throttling_resource_handler.h"
 
 #include "base/logging.h"
 #include "chrome/browser/download/download_request_limiter.h"
 #include "chrome/browser/download/download_util.h"
 #include "content/browser/renderer_host/resource_dispatcher_host.h"
@@ skipping 116 matching lines @@
 }
 
 void DownloadThrottlingResourceHandler::OnRequestClosed() {
   DCHECK(!request_closed_);
   if (request_allowed_)
     next_handler_->OnRequestClosed();
   request_closed_ = true;
 }
 
 void DownloadThrottlingResourceHandler::ContinueDownload(bool allow) {
-  download_util::RecordDownloadCount(
-        download_util::INITIATED_BY_NAVIGATION_COUNT);
+  download_util::RecordDownloadSource(download_util::INITIATED_BY_NAVIGATION);

[cbentzel, 2012/02/06 19:57:29]

Should this be done here or at the BufferedResourceHandler side, and then we
could record a hold-back here?

[Randy Smith (Not in Mondays), 2012/02/07 18:20:18]

Depends how we're thinking of the stats.  I'm more inclined to have everything? 
most things?  in the initiation histogram be actually initiated downloads (i.e.
summing to UNTHROTTLED_COUNT) rather than have to do subtractions to see what
actually ended up being downloaded.  Having said that, I think it would be good
to also count the number of things blocked by DownloadThrottlingResourceHandler,
and I'll add UMA to that effect.  I think I'll leave it in the initiation
histograms enum/UMA, though if you think it should go back into counts, let me
know.

   if (request_closed_)
     return;
 
   request_allowed_ = allow;
   if (allow) {
     // And let the request continue.
     host_->PauseRequest(render_process_host_id_, request_id_, false);
   } else {
     host_->CancelRequest(render_process_host_id_, request_id_, false);
   }
 }