Rolling forward clang, hiding some warnings

tools/clang/blink_gc_plugin/Config.h

 // Copyright 2014 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.
 
 // This file defines the names used by GC infrastructure.
 
 // TODO: Restructure the name determination to use fully qualified names (ala,
 // blink::Foo) so that the plugin can be enabled for all of chromium. Doing so
 // would allow us to catch errors with structures outside of blink that might
 // have unsafe pointers to GC allocated blink structures.
@@ skipping 246 matching lines @@
     if (prefix.size() > str.size())
       return false;
     return str.compare(0, prefix.size(), prefix) == 0;
   }
 
   static bool EndsWith(const std::string& str, const std::string& suffix) {
     if (suffix.size() > str.size())
       return false;
     return str.compare(str.size() - suffix.size(), suffix.size(), suffix) == 0;
   }
+
+  // Test if a template specialization is an instantiation.
+  static bool IsTemplateInstantiation(clang::CXXRecordDecl* record);
 };
 
 #endif  // TOOLS_BLINK_GC_PLUGIN_CONFIG_H_