override chrome:// URLs via extensions.

chrome/browser/browser_about_handler.h

Index: chrome/browser/browser_about_handler.h
diff --git a/chrome/browser/browser_about_handler.h b/chrome/browser/browser_about_handler.h
index dedf929e919cfe09c173126e206a578374dfdfed..87e5e75e06cafabe45ecfd07e3b8f232376c19aa 100644
--- a/chrome/browser/browser_about_handler.h
+++ b/chrome/browser/browser_about_handler.h
@@ -8,6 +8,7 @@
 #define CHROME_BROWSER_BROWSER_ABOUT_HANDLER_H_
 
 class GURL;
+class Profile;
 
 // Decides whether the given URL will be handled by the browser about handler
 // and returns true if so. On true, it may also modify the given URL to be the
@@ -15,7 +16,7 @@ class GURL;
 // handles all "about:" URLs as "about:blank.
 //
 // This is used by BrowserURLHandler.
-bool WillHandleBrowserAboutURL(GURL* url);
+bool WillHandleBrowserAboutURL(GURL* url, Profile* profile);
 
 // We have a few magic commands that don't cause navigations, but rather pop up
 // dialogs. This function handles those cases, and returns true if so. In this