Change infobar creation to use a public static Create() method on the infobar delegate classes.

chrome/browser/download/download_request_infobar_delegate.cc

Index: chrome/browser/download/download_request_infobar_delegate.cc
===================================================================
--- chrome/browser/download/download_request_infobar_delegate.cc	(revision 175396)
+++ chrome/browser/download/download_request_infobar_delegate.cc	(working copy)
@@ -10,6 +10,19 @@
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 
+DownloadRequestInfoBarDelegate::~DownloadRequestInfoBarDelegate() {
+  if (host_)
+    host_->Cancel();
+}
+
+// static
+void DownloadRequestInfoBarDelegate::Create(
+    InfoBarService* infobar_service,
+    DownloadRequestLimiter::TabDownloadState* host) {
+  infobar_service->AddInfoBar(scoped_ptr<InfoBarDelegate>(
+      new DownloadRequestInfoBarDelegate(infobar_service, host)));
+}
+
 DownloadRequestInfoBarDelegate::DownloadRequestInfoBarDelegate(
     InfoBarService* infobar_service,
     DownloadRequestLimiter::TabDownloadState* host)
@@ -17,11 +30,6 @@
       host_(host) {
 }
 
-DownloadRequestInfoBarDelegate::~DownloadRequestInfoBarDelegate() {
-  if (host_)
-    host_->Cancel();
-}
-
 gfx::Image* DownloadRequestInfoBarDelegate::GetIcon() const {
   return &ResourceBundle::GetSharedInstance().GetNativeImageNamed(
       IDR_INFOBAR_MULTIPLE_DOWNLOADS);