Revise about: and chrome: url handling.

chrome/browser/net/url_fixer_upper.h

Index: chrome/browser/net/url_fixer_upper.h
diff --git a/chrome/browser/net/url_fixer_upper.h b/chrome/browser/net/url_fixer_upper.h
index e6096bb4cf9569445e3e20060b5df92a83e7e2e5..f5b5327526dadbfb10bd40c561962c1366c0643f 100644
--- a/chrome/browser/net/url_fixer_upper.h
+++ b/chrome/browser/net/url_fixer_upper.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -41,6 +41,11 @@ namespace URLFixerUpper {
   // be valid, so check the return value's validity or use
   // possibly_invalid_spec().
   //
+  // Schemes "about" and "chrome" are normalized to "chrome://", with slashes.
+  // "about:blank" is unaltered, as Webkit allows frames to access about:blank.
+  // Additionally, if a chrome URL does not have a valid host, as in "about:",
+  // the returned URL will have the host "version", as in "chrome://version".
+  //
   // If |desired_tld| is non-empty, it represents the TLD the user wishes to
   // append in the case of an incomplete domain.  We check that this is not a
   // file path and there does not appear to be a valid TLD already, then append