Blacklist renaming inside blink::protocol namespace.

tools/clang/rewrite_to_chrome_style/tests/namespaces-original.cc

 // Copyright 2016 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.
 
 namespace blink {
 
 // Stuff in blink:: should be renamed.
 void foo();
 
 // Stuff in nested namespaces should be renamed.
 namespace nested {
 void foo();
 }  // namespace nested
 
+// blink::protocol namespace is blacklisted.
+namespace protocol {
+void foo();
+}  // namespace protocol
+
 }  // namespace blink
 
 namespace WTF {
 
 // Stuff in WTF:: should be renamed.
 void foo();
 
 // Stuff in nested namespaces should be renamed.
 namespace nested {
 void foo();
@@ skipping 16 matching lines @@
 void G() {
   blink::foo();
   blink::nested::foo();
   WTF::foo();
   WTF::nested::foo();
   other::foo();
   foo();
   other::blink::foo();
   other::WTF::foo();
 }