components: Cleanup class/struct fwd declarations

components/json_schema/json_schema_validator.h

 // Copyright 2013 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.
 
 #ifndef COMPONENTS_JSON_SCHEMA_JSON_SCHEMA_VALIDATOR_H_
 #define COMPONENTS_JSON_SCHEMA_JSON_SCHEMA_VALIDATOR_H_
 
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 
 namespace base {
 class DictionaryValue;
 class ListValue;
-class StringValue;
 class Value;
 }
 
 //==============================================================================
 // This class implements a subset of JSON Schema.
 // See: http://www.json.com/json-schema-proposal/ for more details.
 //
 // There is also an older JavaScript implementation of the same functionality in
 // chrome/renderer/resources/json_schema.js.
 //
@@ skipping 214 matching lines @@
   bool default_allow_additional_properties_;
 
   // Errors accumulated since the last call to Validate().
   std::vector<Error> errors_;
 
 
   DISALLOW_COPY_AND_ASSIGN(JSONSchemaValidator);
 };
 
 #endif  // COMPONENTS_JSON_SCHEMA_JSON_SCHEMA_VALIDATOR_H_