Replace WebUI::tab_contents() with web_contents() and switch all users to use web_contents.h inst...

chrome/browser/tab_contents/background_contents.cc

Index: chrome/browser/tab_contents/background_contents.cc
===================================================================
--- chrome/browser/tab_contents/background_contents.cc	(revision 116011)
+++ chrome/browser/tab_contents/background_contents.cc	(working copy)
@@ -62,6 +62,10 @@
       content::Details<BackgroundContents>(this));
 }
 
+content::WebContents* BackgroundContents::web_contents() const {
+  return tab_contents_.get();
+}
+
 const GURL& BackgroundContents::GetURL() const {
   return tab_contents_.get() ? tab_contents_->GetURL() : GURL::EmptyGURL();
 }