Implement MediaMetadata artwork in content

content/public/common/media_metadata.h

Index: content/public/common/media_metadata.h
diff --git a/content/public/common/media_metadata.h b/content/public/common/media_metadata.h
index 3d7f13c59366caac20a29ed98b79c0d8a8478d58..96b7b22c9b8a2403c85fed28354eab1e2be02770 100644
--- a/content/public/common/media_metadata.h
+++ b/content/public/common/media_metadata.h
@@ -5,20 +5,31 @@
 #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;
 
@@ -28,11 +39,17 @@ struct CONTENT_EXPORT MediaMetadata {
   // 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