Replace Browser::GetTabContentsAt with GetWebContentsAt and update all callers.

chrome/browser/tab_contents/tab_util.h

Index: chrome/browser/tab_contents/tab_util.h
===================================================================
--- chrome/browser/tab_contents/tab_util.h	(revision 116244)
+++ chrome/browser/tab_contents/tab_util.h	(working copy)
@@ -10,7 +10,6 @@
 class Profile;
 class SiteInstance;
 class TabContents;
-
 namespace content {
 class WebContents;
 }
@@ -28,7 +27,7 @@
 // Returns a new SiteInstance for WebUI and app URLs. Returns the SiteInstance
 // for |source_contents| if it represents the same website as |url|. Returns
 // NULL otherwise.
-SiteInstance* GetSiteInstanceForNewTab(TabContents* source_contents,
+SiteInstance* GetSiteInstanceForNewTab(content::WebContents* source_contents,
                                        Profile* profile,
                                        const GURL& url);