Fix crash when an extension popup shows a JS alert. Showing the alert takes...

chrome/browser/tab_contents/tab_contents.h

Index: chrome/browser/tab_contents/tab_contents.h
diff --git a/chrome/browser/tab_contents/tab_contents.h b/chrome/browser/tab_contents/tab_contents.h
index 33dae8aed5b62c6c8774037c0a5eb41fe9543786..50aae3fbfed4d52b25f6fa2d56eb7489640440f1 100644
--- a/chrome/browser/tab_contents/tab_contents.h
+++ b/chrome/browser/tab_contents/tab_contents.h
@@ -631,6 +631,17 @@ class TabContents : public PageNavigator,
     return request_context_;
   }
 
+  // JavaScriptMessageBoxClient ------------------------------------------------
+  virtual std::wstring GetMessageBoxTitle(const GURL& frame_url,
+                                          bool is_alert);
+  virtual gfx::NativeWindow GetMessageBoxRootWindow();
+  virtual void OnMessageBoxClosed(IPC::Message* reply_msg,
+                                  bool success,
+                                  const std::wstring& prompt);
+  virtual void SetSuppressMessageBoxes(bool suppress_message_boxes);
+  virtual TabContents* AsTabContents() { return this; }
+  virtual ExtensionHost* AsExtensionHost() { return NULL; }
+
  private:
   friend class NavigationController;
   // Used to access the child_windows_ (ConstrainedWindowList) for testing
@@ -951,17 +962,6 @@ class TabContents : public PageNavigator,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
-
-  // JavaScriptMessageBoxClient ------------------------------------------------
-  virtual std::wstring GetMessageBoxTitle(const GURL& frame_url,
-                                          bool is_alert);
-  virtual gfx::NativeWindow GetMessageBoxRootWindow();
-  virtual void OnMessageBoxClosed(IPC::Message* reply_msg,
-                                  bool success,
-                                  const std::wstring& prompt);
-  virtual void SetSuppressMessageBoxes(bool suppress_message_boxes);
-  virtual TabContents* AsTabContents() { return this; }
-
   // Data for core operation ---------------------------------------------------
 
   // Delegate for notifying our owner about stuff. Not owned by us.