Cancel prerender when we discover a download starting from a page we are prer...

chrome/browser/prerender/prerender_contents.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.
 
 #include "chrome/browser/prerender/prerender_contents.h"
 
 #include "base/metrics/histogram.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/background_contents_service.h"
 #include "chrome/browser/browsing_instance.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
+#include "chrome/browser/renderer_host/resource_request_details.h"
 #include "chrome/browser/renderer_host/site_instance.h"
 #include "chrome/browser/renderer_preferences_util.h"
 #include "chrome/browser/ui/login/login_prompt.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/common/view_types.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/render_messages_params.h"
 #include "ui/gfx/rect.h"
@@ skipping 51 matching lines @@
                  Source<Profile>(profile_));
   render_view_host_->CreateRenderView(string16());
 
   // Register to cancel if Authentication is required.
   registrar_.Add(this, NotificationType::AUTH_NEEDED,
                  NotificationService::AllSources());
 
   registrar_.Add(this, NotificationType::AUTH_CANCELLED,
                  NotificationService::AllSources());
 
+  // Register all responses to see if we should cancel.
+  registrar_.Add(this, NotificationType::DOWNLOAD_STARTED,

[cbentzel, 2011/02/09 12:19:15]

Instead of registering with AllSources, you could register with
Source<RenderViewHostDelegate>(this). That way the filtering is done in the
NotificationService rather than here. 

[dominich, 2011/02/09 22:33:30]

Done.

+                 NotificationService::AllSources());
+
   DCHECK(load_start_time_.is_null());
   load_start_time_ = base::TimeTicks::Now();
 
   ViewMsg_Navigate_Params params;
   params.url = prerender_url_;
   params.transition = PageTransition::LINK;
   params.navigation_type = ViewMsg_Navigate_Params::PRERENDER;
   render_view_host_->Navigate(params);
 }
 
@@ skipping 104 matching lines @@
       LoginNotificationDetails* details_ptr =
           Details<LoginNotificationDetails>(details).ptr();
       LoginHandler* handler = details_ptr->handler();
       DCHECK(handler != NULL);
       RenderViewHostDelegate* delegate = handler->GetRenderViewHostDelegate();
       if (controller == NULL && delegate == this)
         Destroy(FINAL_STATUS_AUTH_NEEDED);
       break;
     }
 
+    case NotificationType::DOWNLOAD_STARTED: {
+      // If the download is started from a RenderViewHost that we are
+      // delegating, kill the prerender. This will also stop the download and
+      // navigating to the page will restart it as expected.
+      RenderViewHostDelegate* rvhd =
+          Source<RenderViewHostDelegate>(source).ptr();
+      if (rvhd == this) {
+        Destroy(FINAL_STATUS_DOWNLOAD);

[cbentzel, 2011/02/09 12:11:14]

Nit: I'd like an explicit return here, since Destroy is calling delete this.

It's OK for now, but if any logic went below the switch statement it might be
problematic.

[dominich, 2011/02/09 22:33:30]

I'll add the same to the AUTH_* cases above.

[dominich, 2011/02/09 22:33:30]

Done.

+      }
+      break;
+    }
+
     default:
       NOTREACHED() << "Unexpected notification sent.";
       break;
   }
 }
 
 void PrerenderContents::OnMessageBoxClosed(IPC::Message* reply_msg,
                                            bool success,
                                            const std::wstring& prompt) {
   render_view_host_->JavaScriptMessageBoxClosed(reply_msg, success, prompt);
@@ skipping 115 matching lines @@
 
 void PrerenderContents::DidStopLoading() {
   has_stopped_loading_ = true;
 }
 
 void PrerenderContents::Destroy(FinalStatus final_status) {
   prerender_manager_->RemoveEntry(this);
   set_final_status(final_status);
   delete this;
 }