PrerenderContents uses RESOURCE_RECEIVED_REDIRECT notification.

chrome/browser/prerender/prerender_contents.cc

Index: chrome/browser/prerender/prerender_contents.cc
diff --git a/chrome/browser/prerender/prerender_contents.cc b/chrome/browser/prerender/prerender_contents.cc
index c142f159881f75390482be7dbeb5bf376b5da973..d00b66f77ac7241cee550ccaeafd10ff9edc0f78 100644
--- a/chrome/browser/prerender/prerender_contents.cc
+++ b/chrome/browser/prerender/prerender_contents.cc
@@ -22,6 +22,7 @@
 #include "content/browser/browsing_instance.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/renderer_host/resource_dispatcher_host.h"
+#include "content/browser/renderer_host/resource_request_details.h"
 #include "content/browser/site_instance.h"
 #include "content/common/notification_service.h"
 #include "content/common/view_messages.h"
@@ -138,6 +139,10 @@ void PrerenderContents::StartPrerendering() {
   registrar_.Add(this, NotificationType::DOWNLOAD_INITIATED,
                  NotificationService::AllSources());
 
+  // Register for redirects.

[Charlie Reis, 2011/04/11 21:15:52]

Please add "from this RenderViewHostDelegate," since that's useful for
understanding why this is correct.

[cbentzel, 2011/04/12 18:07:59]

Done.

+  registrar_.Add(this, NotificationType::RESOURCE_RECEIVED_REDIRECT,
+                 Source<RenderViewHostDelegate>(this));
+
   DCHECK(load_start_time_.is_null());
   load_start_time_ = base::TimeTicks::Now();
 
@@ -322,6 +327,23 @@ void PrerenderContents::Observe(NotificationType type,
       break;
     }
 
+    case NotificationType::RESOURCE_RECEIVED_REDIRECT: {
+      // RESOURCE_RECEIVED_REDIRECT can come for any resource on a page.
+      // If it's a redirect on the top-level resource, the name needs
+      // to be remembered for future matching, and if it redirects to
+      // an https resource, it needs to be canceled. If a subresource
+      // is redirected, nothing changes.

[Charlie Reis, 2011/04/11 21:15:52]

How are you distinguishing whether it's top-level or a sub-resource?  It's
possible for the same URL to be used for both.  Should you be checking
details->resource_type()?

[cbentzel, 2011/04/11 21:18:35]

I'll change to resource_type(). This was using "MatchesURL" to see if the
previous URL is one of the previously seen URL in the top level page.

[cbentzel, 2011/04/12 18:07:59]

resource_type() is much clearer about what's going on than MatchesURL [and
potentially a little faster].

+      DCHECK(Source<RenderViewHostDelegate>(source).ptr() == this);
+      ResourceRedirectDetails* resource_redirect_details =
+          Details<ResourceRedirectDetails>(details).ptr();
+      CHECK(resource_redirect_details != NULL);

[Charlie Reis, 2011/04/11 21:15:52]

I think Chrome style is to omit the "!= NULL".

[cbentzel, 2011/04/12 18:07:59]

Done.

+      if (MatchesURL(resource_redirect_details->url())) {
+        if (!AddAliasURL(resource_redirect_details->new_url()))
+          Destroy(FINAL_STATUS_HTTPS);
+      }
+      break;
+    }
+
     default:
       NOTREACHED() << "Unexpected notification sent.";
       break;
@@ -412,8 +434,6 @@ bool PrerenderContents::OnMessageReceived(const IPC::Message& message) {
   IPC_BEGIN_MESSAGE_MAP_EX(PrerenderContents, message, message_is_ok)
     IPC_MESSAGE_HANDLER(ViewHostMsg_DidStartProvisionalLoadForFrame,
                         OnDidStartProvisionalLoadForFrame)
-    IPC_MESSAGE_HANDLER(ViewHostMsg_DidRedirectProvisionalLoad,
-                        OnDidRedirectProvisionalLoad)
     IPC_MESSAGE_HANDLER(ViewHostMsg_UpdateFaviconURL, OnUpdateFaviconURL)
     IPC_MESSAGE_HANDLER(ViewHostMsg_MaybeCancelPrerender,
                         OnMaybeCancelPrerender)
@@ -441,13 +461,6 @@ void PrerenderContents::OnDidStartProvisionalLoadForFrame(int64 frame_id,
   }
 }
 
-void PrerenderContents::OnDidRedirectProvisionalLoad(int32 page_id,
-                                                     const GURL& source_url,
-                                                     const GURL& target_url) {
-  if (!AddAliasURL(target_url))
-    Destroy(FINAL_STATUS_HTTPS);
-}
-
 void PrerenderContents::OnUpdateFaviconURL(int32 page_id,
                                            const GURL& icon_url) {
   icon_url_ = icon_url;