Cleanup: remove redundant tab close observation from TabModalConfirmDialogDelegate

chrome/browser/ui/tab_modal_confirm_dialog_delegate.cc

Index: chrome/browser/ui/tab_modal_confirm_dialog_delegate.cc
diff --git a/chrome/browser/ui/tab_modal_confirm_dialog_delegate.cc b/chrome/browser/ui/tab_modal_confirm_dialog_delegate.cc
index c8e1a588267fdb65c9dd7c1a5024eb1edd53c050..d2711dcdaeb19f080e298bd4718923096bcd0e7b 100644
--- a/chrome/browser/ui/tab_modal_confirm_dialog_delegate.cc
+++ b/chrome/browser/ui/tab_modal_confirm_dialog_delegate.cc
@@ -4,23 +4,14 @@
 
 #include "chrome/browser/ui/tab_modal_confirm_dialog_delegate.h"
 
-#include "chrome/browser/chrome_notification_types.h"
-#include "content/public/browser/navigation_controller.h"
-#include "content/public/browser/notification_source.h"
-#include "content/public/browser/web_contents.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 
-using content::NavigationController;
 using content::WebContents;
 
-TabModalConfirmDialogDelegate::TabModalConfirmDialogDelegate(
-    WebContents* web_contents)
+TabModalConfirmDialogDelegate::TabModalConfirmDialogDelegate()
     : operations_delegate_(NULL),
       closing_(false) {
-  NavigationController* controller = &web_contents->GetController();
-  registrar_.Add(this, chrome::NOTIFICATION_TAB_CLOSING,
-                 content::Source<NavigationController>(controller));
 }
 
 TabModalConfirmDialogDelegate::~TabModalConfirmDialogDelegate() {
@@ -61,18 +52,6 @@ void TabModalConfirmDialogDelegate::LinkClicked(
   CloseDialog();
 }
 
-void TabModalConfirmDialogDelegate::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
-  // Close the dialog if the tab is closed.
-  if (type == chrome::NOTIFICATION_TAB_CLOSING) {
-    Cancel();
-  } else {
-    NOTREACHED();
-  }
-}
-
 gfx::Image* TabModalConfirmDialogDelegate::GetIcon() {
   return NULL;
 }