Revert 110262 - Have ExtensionHost use TabContents instead of RenderViewHost. Try #2.

content/browser/tab_contents/tab_contents.cc

Index: content/browser/tab_contents/tab_contents.cc
===================================================================
--- content/browser/tab_contents/tab_contents.cc	(revision 110269)
+++ content/browser/tab_contents/tab_contents.cc	(working copy)
@@ -203,6 +203,7 @@
       temporary_zoom_settings_(false),
       content_restrictions_(0),
       view_type_(content::VIEW_TYPE_TAB_CONTENTS) {
+
   render_manager_.Init(browser_context, site_instance, routing_id);
 
   // We have the initial size of the view be based on the size of the passed in
@@ -1703,12 +1704,6 @@
     delegate()->LoadProgressChanged(progress);
 }
 
-void TabContents::DocumentAvailableInMainFrame(
-    RenderViewHost* render_view_host) {
-  FOR_EACH_OBSERVER(TabContentsObserver, observers_,
-                    DocumentAvailableInMainFrame());
-}
-
 void TabContents::DocumentOnLoadCompletedInMainFrame(
     RenderViewHost* render_view_host,
     int32 page_id) {