Move most of the remaining users of WebContentsObserver::tab_contents() to use web_contents().

chrome/browser/automation/automation_provider_observers.h

Index: chrome/browser/automation/automation_provider_observers.h
===================================================================
--- chrome/browser/automation/automation_provider_observers.h	(revision 115777)
+++ chrome/browser/automation/automation_provider_observers.h	(working copy)
@@ -74,14 +74,18 @@
 }
 #endif  // defined(OS_CHROMEOS)
 
+namespace IPC {
+class Message;
+}
+
+namespace content {
+class WebContents;
+}
+
 namespace history {
 class TopSites;
 }
 
-namespace IPC {
-class Message;
-}
-
 namespace policy {
 class BrowserPolicyConnector;
 }
@@ -686,7 +690,7 @@
  public:
   PageTranslatedObserver(AutomationProvider* automation,
                          IPC::Message* reply_message,
-                         TabContents* tab_contents);
+                         content::WebContents* web_contents);
   virtual ~PageTranslatedObserver();
 
   // content::NotificationObserver interface.