Implement MediaMetadata artwork in content

content/public/common/media_metadata.h

 // Copyright 2016 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_MEDIA_METADATA_H_
 #define CONTENT_PUBLIC_COMMON_MEDIA_METADATA_H_
 
+#include <vector>
+
+#include "base/optional.h"
 #include "base/strings/string16.h"
 #include "content/common/content_export.h"
+#include "content/public/common/manifest.h"
 
 namespace content {
 
 // The MediaMetadata is a structure carrying information associated to a
 // content::MediaSession.
 struct CONTENT_EXPORT MediaMetadata {
+  // TODO(zqzhang): move |Manifest::Icon| to a common place.

[palmer, 2016/06/20 21:34:21]

It's good to have a crbug link.

[Zhiqiang Zhang (Slow), 2016/06/21 11:08:42]

Done.

+  using Artwork = Manifest::Icon;
+
   MediaMetadata();
   ~MediaMetadata();
 
   bool operator==(const MediaMetadata& other) const;
   bool operator!=(const MediaMetadata& other) const;
 
+  // Apply validity checks and sanitize |artwork|. Returns null if
+  // |artwork| does not pass validity checks.
+  static base::Optional<Artwork> SanitizeArtwork(const Artwork& artwork);
+
   // Title associated to the MediaSession.
   base::string16 title;
 
   // Artist associated to the MediaSession.
   base::string16 artist;
 
   // Album associated to the MediaSession.
   base::string16 album;
 
+  std::vector<Artwork> artwork;

[palmer, 2016/06/20 21:34:21]

Nit: Since this is a vector, I might call it |artworks| or |artwork_list| or
something like that.

[Zhiqiang Zhang (Slow), 2016/06/21 11:08:42]

Yes. The naming here is confusing, which comes from the MediaMetadata spec. We
are addressing the naming spec now. We'll update the code (TBR should be okay?)
once the spec has been fixed.

+
   // Maximum length for all the strings inside the MediaMetadata when it is sent
   // over IPC. The renderer process should truncate the strings before sending
   // the MediaMetadata and the browser process must do the same when receiving
   // it.
   static const size_t kMaxIPCStringLength;
+  // Maximum size of Artwork. The renderer process should remove the sizes in
+  // artwork that are out of bound before sending the MediaMetadata and the
+  // browser process must do the same when receiving it.
+  static const int kMaxIconSize;
 };
 
 }  // namespace content
 
 #endif // CONTENT_PUBLIC_COMMON_MEDIA_METADATA_H_