chromeos: Fix DOMUI about:credits link.

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 e0a0dbf458db995cd7f1f15fed20ce316023a0c2..46ae1008624fc0c94ed0059c00a3debf2d50c602 100644
--- a/chrome/browser/browser_about_handler.h
+++ b/chrome/browser/browser_about_handler.h
@@ -26,6 +26,10 @@ class Profile;
 // This is used by BrowserURLHandler.
 bool WillHandleBrowserAboutURL(GURL* url, Profile* profile);
 
+// Register the data source for chrome://about URLs.
+// Safe to call multiple times.
+void InitializeAboutDataSource();
+
 // 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
 // case, normal tab navigation should be skipped.