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"
@@ skipping 64 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_INITIATED,
+                 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);
 }
 
 void PrerenderContents::set_final_status(FinalStatus final_status) {
   DCHECK(final_status >= FINAL_STATUS_USED && final_status < FINAL_STATUS_MAX);
   DCHECK_EQ(FINAL_STATUS_MAX, final_status_);
+
   final_status_ = final_status;
 }
 
 PrerenderContents::FinalStatus PrerenderContents::final_status() const {
   return final_status_;
 }
 
 PrerenderContents::~PrerenderContents() {
   DCHECK(final_status_ != FINAL_STATUS_MAX);
   UMA_HISTOGRAM_ENUMERATION("Prerender.FinalStatus",
@@ skipping 71 matching lines @@
   return false;
 }
 
 void PrerenderContents::Observe(NotificationType type,
                                 const NotificationSource& source,
                                 const NotificationDetails& details) {
   switch (type.value) {
     case NotificationType::PROFILE_DESTROYED:
       Destroy(FINAL_STATUS_PROFILE_DESTROYED);
       return;
+
     case NotificationType::APP_TERMINATING:
       Destroy(FINAL_STATUS_APP_TERMINATING);
       return;
 
     case NotificationType::AUTH_NEEDED:
     case NotificationType::AUTH_CANCELLED: {
       // Prerendered pages have a NULL controller and the login handler should
       // be referencing us as the render view host delegate.
       NavigationController* controller =
           Source<NavigationController>(source).ptr();
       LoginNotificationDetails* details_ptr =
           Details<LoginNotificationDetails>(details).ptr();
       LoginHandler* handler = details_ptr->handler();
       DCHECK(handler != NULL);
       RenderViewHostDelegate* delegate = handler->GetRenderViewHostDelegate();
-      if (controller == NULL && delegate == this)
+      if (controller == NULL && delegate == this) {
         Destroy(FINAL_STATUS_AUTH_NEEDED);
+        return;
+      }
       break;
     }
 
+    case NotificationType::DOWNLOAD_INITIATED: {
+      // If the download is started from a RenderViewHost that we are
+      // delegating, kill the prerender. This cancels any pending requests
+      // though the download never actually started thanks to the
+      // DownloadRequestLimiter.
+      DCHECK(details == NotificationService::NoDetails());
+      RenderViewHost* rvh = Source<RenderViewHost>(source).ptr();
+      if (rvh->delegate() == this) {

[cbentzel, 2011/02/10 19:32:18]

May not hurt to be defensive and check that rvh is non-NULL. 

[dominich, 2011/02/10 20:02:17]

Done.

+        Destroy(FINAL_STATUS_DOWNLOAD);
+      }
+      return;

[cbentzel, 2011/02/10 19:32:18]

move return next to Destroy and make this break, to be similar to Observe.

[dominich, 2011/02/10 20:02:17]

Done.

+    }
+
     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 121 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;
 }