Extend |is_type_trait_value| matcher to cover |blink| namespace.

tools/clang/rewrite_to_chrome_style/tests/fields-expected.cc

 // Copyright 2015 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 {
 
 // Note: do not add any copy or move constructors to this class: doing so will
 // break test coverage that we don't clobber the class name by trying to emit
 // replacements for synthesized functions.
 class C {
@@ skipping 47 matching lines @@
 };
 
 // Unions also use struct-style naming.
 union U {
   char four_chars[4];
   short two_shorts[2];
   int one_hopefully_four_byte_int;
   int has_prefix_;
 };
 
+// https://crbug.com/640749#c1: Some type traits are inside blink namespace.
+struct IsGarbageCollectedMixin {
+  static const bool value = true;
+};
+
 }  // namespace blink
 
 namespace WTF {
 
 // We don't want to capitalize fields in type traits
 // (i.e. no |value| -> |kValue| rename is undesirable below).
 struct TypeTrait1 {
   static const bool value = true;
 };
 
-// Some type traits  are implemented as classes, not structs
+// Some type traits are implemented as classes, not structs
 // (e.g. WTF::IsGarbageCollectedType or WTF::IsAssignable).
 template <typename T>
 class TypeTrait2 {
  public:
   static const bool value = false;
 };
 template <>
 class TypeTrait2<void> {
  public:
   static const bool value = false;
 };
 
 };  // namespace WTF
 
 void F() {
   // Test that references to a static field are correctly rewritten.
   blink::C::instance_count_++;
   // Force instantiation of a copy constructor for blink::C to make sure field
   // initializers for synthesized functions don't cause weird rewrites.
   blink::C c;
   blink::C c2 = c;
 
   bool b1 = WTF::TypeTrait1::value;
   bool b2 = WTF::TypeTrait2<void>::value;
 }