infobars: Use TCW directly in InfoBar to remove the delegate.

chrome/browser/tab_contents/infobar_container.h

Index: chrome/browser/tab_contents/infobar_container.h
diff --git a/chrome/browser/tab_contents/infobar_container.h b/chrome/browser/tab_contents/infobar_container.h
index 1be2b817b6e0e4e4abe7d37e4bfa60e51e0b6d27..0b3eb5b2af0de8a1ebd79e29d069a5c47243a9d2 100644
--- a/chrome/browser/tab_contents/infobar_container.h
+++ b/chrome/browser/tab_contents/infobar_container.h
@@ -72,11 +72,6 @@ class InfoBarContainer : public NotificationObserver {
   // anything necessary to respond, e.g. re-layout.
   void OnInfoBarStateChanged(bool is_animating);
 
-  // Removes the specified InfoBarDelegate from the selected TabContentsWrapper.
-  // This will notify us back and cause us to close the InfoBar.  This is called
-  // from the InfoBar's close button handler.
-  void RemoveDelegate(InfoBarDelegate* delegate);
-
   // Called by |infobar| to request that it be removed from the container, as it
   // is about to delete itself.  At this point, |infobar| should already be
   // hidden.