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

chrome/browser/google/google_url_tracker_infobar_delegate.h

Index: chrome/browser/google/google_url_tracker_infobar_delegate.h
===================================================================
--- chrome/browser/google/google_url_tracker_infobar_delegate.h	(revision 175396)
+++ chrome/browser/google/google_url_tracker_infobar_delegate.h	(working copy)
@@ -14,9 +14,12 @@
 // changed.
 class GoogleURLTrackerInfoBarDelegate : public ConfirmInfoBarDelegate {
  public:
-  GoogleURLTrackerInfoBarDelegate(InfoBarService* infobar_service,
-                                  GoogleURLTracker* google_url_tracker,
-                                  const GURL& search_url);
+  // Creates a Google URL tracker delegate and adds it to |infobar_service|.
+  // Returns the delegate if it was successfully added.
+  static GoogleURLTrackerInfoBarDelegate* Create(
+      InfoBarService* infobar_service,
+      GoogleURLTracker* google_url_tracker,
+      const GURL& search_url);
 
   // ConfirmInfoBarDelegate:
   virtual bool Accept() OVERRIDE;
@@ -37,6 +40,9 @@
   virtual void Close(bool redo_search);
 
  protected:
+  GoogleURLTrackerInfoBarDelegate(InfoBarService* infobar_service,
+                                  GoogleURLTracker* google_url_tracker,
+                                  const GURL& search_url);
   virtual ~GoogleURLTrackerInfoBarDelegate();
 
  private: