Added DownloadProcessHandle class.

chrome/browser/download/download_util.cc

 // Copyright (c) 2011 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.
 //
 // Download utility implementation
 
 #include "chrome/browser/download/download_util.h"
 
 #if defined(OS_WIN)
 #include <shobjidl.h>
@@ skipping 795 matching lines @@
 
   rdh->BeginDownload(url,
                      referrer,
                      save_info,
                      true,  // Show "Save as" UI.
                      render_process_host_id,
                      render_view_id,
                      context);
 }
 
-void CancelDownloadRequest(ResourceDispatcherHost* rdh,
-                           int render_process_id,
-                           int request_id) {
+static void CancelDownloadRequestOnIOThread(
+    ResourceDispatcherHost* rdh, DownloadProcessHandle process_handle) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   // |rdh| may be NULL in unit tests.
-  if (rdh)
-    rdh->CancelRequest(render_process_id, request_id, false);
+  if (!rdh)
+    return;
+
+  rdh->CancelRequest(process_handle.child_id(),
+                     process_handle.request_id(),
+                     false);
+}
+
+void CancelDownloadRequest(ResourceDispatcherHost* rdh,
+                           DownloadProcessHandle process_handle) {
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      NewRunnableFunction(&download_util::CancelDownloadRequestOnIOThread,
+                          rdh, process_handle));
 }
 
 void NotifyDownloadInitiated(int render_process_id, int render_view_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   RenderViewHost* rvh = RenderViewHost::FromID(render_process_id,
                                                render_view_id);
   if (!rvh)
     return;
 
   NotificationService::current()->Notify(NotificationType::DOWNLOAD_INITIATED,
@@ skipping 61 matching lines @@
     // Extensions that are not from the gallery are considered dangerous.
     ExtensionService* service = profile->GetExtensionService();
     if (!service ||
         !service->IsDownloadFromGallery(info->url(), info->referrer_url))
       return true;
   }
   return false;
 }
 
 }  // namespace download_util