Plumb redirect info out of net, through content, and into child processes.

content/browser/download/download_resource_handler.cc

Index: content/browser/download/download_resource_handler.cc
diff --git a/content/browser/download/download_resource_handler.cc b/content/browser/download/download_resource_handler.cc
index 0a19163c9c3f8ae40a9532e13780c89acac15fab..1fe8d11756fd64153909f5648dc0583e5d439fb4 100644
--- a/content/browser/download/download_resource_handler.cc
+++ b/content/browser/download/download_resource_handler.cc
@@ -141,12 +141,9 @@ bool DownloadResourceHandler::OnUploadProgress(uint64 position,
 }
 
 bool DownloadResourceHandler::OnRequestRedirected(
-    const GURL& url,
+    const net::RedirectInfo& redirect_info,
     ResourceResponse* response,
     bool* defer) {

[mmenke, 2014/07/17 16:55:09]

Was code you removed redundant, or should we be setting the policy somewhere for
downloads?

Hrm...Wonder if there's a test for this.  Suspect not.

[davidben, 2014/07/17 22:03:54]

Hrm, oh it's not quite redundant because requests may begin with
DownloadResourceHandler attached. I've moved it to RDH::BeginDownload. (If this
download began life at the BRH, it would never see a redirect, so that's the
only case.)

-  // We treat a download as a main frame load, and thus update the policy URL
-  // on redirects.
-  request()->set_first_party_for_cookies(url);
   return true;
 }