manifest: add theme_color value to the manifest

content/public/common/manifest.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_PUBLIC_COMMON_MANIFEST_H_
 #define CONTENT_PUBLIC_COMMON_MANIFEST_H_
 
 #include <vector>
 
 #include "base/strings/nullable_string16.h"
@@ skipping 94 matching lines @@
   // Empty if the parsing failed, the field was not present, empty or all the
   // applications inside the array were invalid. The order of the array
   // indicates the priority of the application to use.
   std::vector<RelatedApplication> related_applications;
 
   // A boolean that is used as a hint for the user agent to say that related
   // applications should be preferred over the web application. False if missing
   // or there is a parsing failure.
   bool prefer_related_applications;
 
+  // Set to kInvalidOrMissingThemeColor if parsing failed or field is not
+  // present.
+  int64_t theme_color;

[nasko, 2015/07/20 11:07:03]

I'm sorry I missed this earlier. Is there a reason why we are using 64bit value
here? It seems that the source of the data is 32bit and the value range is in
the 32bit space.

[Lalit Maganti, 2015/07/20 11:23:49]

Yes. The color is represented as an unsigned 32 bit integer but we need -1 to
represent a parsing issue. Unfortunately it causes a wastage of 31 bits but it
is the most elegant solution I can come up with.

+
   // This is a proprietary extension of the web Manifest, double-check that it
   // is okay to use this entry.
   // Null if parsing failed or the field was not present.
   base::NullableString16 gcm_sender_id;
 
   // Maximum length for all the strings inside the Manifest when it is sent over
   // IPC. The renderer process should truncate the strings before sending the
   // Manifest and the browser process must do the same when receiving it.
   static const size_t kMaxIPCStringLength;
+
+  // Constant representing an invalid theme color. Set to -1.
+  static const int64_t kInvalidOrMissingThemeColor;
 };
 
 } // namespace content
 
 #endif // CONTENT_PUBLIC_COMMON_MANIFEST_H_