[WIP] Use Optional<SkColor> instead of int64 for colors in Manifest.

content/renderer/manifest/manifest_parser.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 CONTENT_RENDERER_MANIFEST_MANIFEST_PARSER_H_
 #define CONTENT_RENDERER_MANIFEST_MANIFEST_PARSER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 48 matching lines @@
 
   // Helper function to parse strings present on a given |dictionary| in a given
   // field identified by its |key|.
   // Returns the parsed string if any, a null string if the parsing failed.
   base::NullableString16 ParseString(const base::DictionaryValue& dictionary,
                                      const std::string& key,
                                      TrimType trim);
 
   // Helper function to parse colors present on a given |dictionary| in a given
   // field identified by its |key|.
-  // Returns the parsed color as an int64_t if any,
-  // Manifest::kInvalidOrMissingColor if the parsing failed.
-  int64_t ParseColor(const base::DictionaryValue& dictionary,
-                     const std::string& key);
+  // Returns the parsed color as Optional<SkColor>; if the parsing failed, the
+  // Optional<> will be empty.
+  base::Optional<SkColor> ParseColor(const base::DictionaryValue& dictionary,
+                                     const std::string& key);
 
   // Helper function to parse URLs present on a given |dictionary| in a given
   // field identified by its |key|. The URL is first parsed as a string then
   // resolved using |base_url|.
   // Returns a GURL. If the parsing failed, the GURL will not be valid.
   GURL ParseURL(const base::DictionaryValue& dictionary,
                 const std::string& key,
                 const GURL& base_url);
 
   // Parses the 'name' field of the manifest, as defined in:
@@ skipping 81 matching lines @@
       const base::DictionaryValue& dictionary);
 
   // Parses the 'prefer_related_applications' field on the manifest, as defined
   // in:
   // https://w3c.github.io/manifest/#dfn-steps-for-processing-the-prefer_related_applications-member
   // returns true iff the field could be parsed as the boolean true.
   bool ParsePreferRelatedApplications(const base::DictionaryValue& dictionary);
 
   // Parses the 'theme_color' field of the manifest, as defined in:
   // http://w3c.github.io/manifest/#dfn-steps-for-processing-the-theme_color-member
-  // Returns the parsed theme color if any,
-  // Manifest::kInvalidOrMissingColor if the parsing failed.
-  int64_t ParseThemeColor(const base::DictionaryValue& dictionary);
+  // Returns the parsed theme color wrapped in an Optional<> if any, empty
+  // Optional<> if the parsing failed.
+  base::Optional<SkColor> ParseThemeColor(
+      const base::DictionaryValue& dictionary);
 
   // Parses the 'background_color' field of the manifest, as defined in:
   // http://w3c.github.io/manifest/#dfn-steps-for-processing-the-background_color-member
-  // Returns the parsed background color if any,
-  // Manifest::kInvalidOrMissingColor if the parsing failed.
-  int64_t ParseBackgroundColor(const base::DictionaryValue& dictionary);
+  // Returns the parsed background color wrapped in an Optional<> if any, empty
+  // Optional<> if the parsing failed.
+  base::Optional<SkColor> ParseBackgroundColor(
+      const base::DictionaryValue& dictionary);
 
   // Parses the 'gcm_sender_id' field of the manifest.
   // This is a proprietary extension of the Web Manifest specification.
   // Returns the parsed string if any, a null string if the parsing failed.
   base::NullableString16 ParseGCMSenderID(
       const base::DictionaryValue& dictionary);
 
   void AddErrorInfo(const std::string& error_msg,
                     bool critical = false,
                     int error_line = 0,
                     int error_column = 0);
 
   const base::StringPiece& data_;
   GURL manifest_url_;
   GURL document_url_;
 
   bool failed_;
   Manifest manifest_;
   std::vector<ManifestDebugInfo::Error> errors_;
 
   DISALLOW_COPY_AND_ASSIGN(ManifestParser);
 };
 
 } // namespace content
 
 #endif  // CONTENT_RENDERER_MANIFEST_MANIFEST_PARSER_H_