Add content ID scheme to //url/url_constants.*

url/url_constants.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.
 
 #ifndef URL_URL_CONSTANTS_H_
 #define URL_URL_CONSTANTS_H_
 
 #include <stddef.h>
 
 #include "url/url_export.h"
 
 namespace url {
 
 URL_EXPORT extern const char kAboutBlankURL[];
 
 URL_EXPORT extern const char kAboutScheme[];
 URL_EXPORT extern const char kBlobScheme[];
 // The content scheme is specific to Android for identifying a stored file.
 URL_EXPORT extern const char kContentScheme[];
+URL_EXPORT extern const char kContentIDScheme[];
 URL_EXPORT extern const char kDataScheme[];
 URL_EXPORT extern const char kFileScheme[];
 URL_EXPORT extern const char kFileSystemScheme[];
 URL_EXPORT extern const char kFtpScheme[];
 URL_EXPORT extern const char kGopherScheme[];
 URL_EXPORT extern const char kHttpScheme[];
 URL_EXPORT extern const char kHttpsScheme[];
 URL_EXPORT extern const char kJavaScriptScheme[];
 URL_EXPORT extern const char kMailToScheme[];
 URL_EXPORT extern const char kWsScheme[];
 URL_EXPORT extern const char kWssScheme[];
 
 // Used to separate a standard scheme and the hostname: "://".
 URL_EXPORT extern const char kStandardSchemeSeparator[];
 
 URL_EXPORT extern const size_t kMaxURLChars;
 
 }  // namespace url
 
 #endif  // URL_URL_CONSTANTS_H_