Implement MediaMetadata artwork in content

content/public/common/media_metadata.cc

Index: content/public/common/media_metadata.cc
diff --git a/content/public/common/media_metadata.cc b/content/public/common/media_metadata.cc
index dc3824c25b0cdc82b515387caec50f9ea356f6b7..1214f22bf80ddb3b2e3ba0f8efa4418ab75b541c 100644
--- a/content/public/common/media_metadata.cc
+++ b/content/public/common/media_metadata.cc
@@ -4,20 +4,65 @@
 
 #include "content/public/common/media_metadata.h"
 
+#include <algorithm>
+#include <iterator>
+
 namespace content {
 
+namespace {
+
+const size_t kMaxArtworkSrcLength = 4 * 1024;
+// Maximum type length of Artwork, which conforms to RFC 4288
+// (https://tools.ietf.org/html/rfc4288).
+const size_t kMaxArtworkTypeLength = 2 * 127 + 1;
+const size_t kMaxNumberOfArtworkSizes = 10;
+
+}  // anonymous namespace
+
 const size_t MediaMetadata::kMaxIPCStringLength = 4 * 1024;
+const size_t MediaMetadata::kMaxNumberOfArtworkImages = 10;
 
 MediaMetadata::MediaMetadata() = default;
 
 MediaMetadata::~MediaMetadata() = default;
 
+MediaMetadata::MediaMetadata(const MediaMetadata& other) = default;
+
 bool MediaMetadata::operator==(const MediaMetadata& other) const {
-  return title == other.title && artist == other.artist && album == other.album;
+  return title == other.title && artist == other.artist &&
+      album == other.album && artwork == other.artwork;
 }
 
 bool MediaMetadata::operator!=(const MediaMetadata& other) const {
   return !this->operator==(other);
 }
 
+base::Optional<MediaMetadata::Artwork> MediaMetadata::SanitizeArtwork(

[DaleCurtis, 2016/06/29 17:20:20]

What's the point of sanitizing the artwork? Why not just fail if invalid options
are used?

[Zhiqiang Zhang (Slow), 2016/06/29 19:16:13]

The artwork come from blink, and can be anything, so we sanitize it before
sending to the browser through IPC.

Sometimes it may be legal but improper to be sent through IPC (e.g. src is too
long), so I think we should not fail.

+    const MediaMetadata::Artwork& artwork) {
+  if (!artwork.src.is_valid() || !artwork.src.IsStandard() ||
+      (!artwork.src.SchemeIsHTTPOrHTTPS() &&
+       !artwork.src.SchemeIsFile()) ||
+      artwork.src.spec().size() > kMaxArtworkSrcLength) {
+    return base::nullopt;
+  }
+  // Early return if artwork is sane.
+  if (artwork.type.string().size() <= kMaxArtworkTypeLength &&
+      artwork.sizes.size() <= kMaxNumberOfArtworkSizes)

[DaleCurtis, 2016/06/29 17:20:20]

Needs {}

[Zhiqiang Zhang (Slow), 2016/06/29 19:16:13]

Done.

+    return artwork;
+
+  Artwork sanitized_artwork;
+  sanitized_artwork.src = artwork.src;
+  sanitized_artwork.type = artwork.type.is_null() ?
+      base::NullableString16() :
+      base::NullableString16(
+          artwork.type.string().substr(0, kMaxArtworkTypeLength),
+          false);
+  for (size_t i = 0;

[DaleCurtis, 2016/06/29 17:20:20]

{}

[Zhiqiang Zhang (Slow), 2016/06/29 19:16:13]

Done.

+       i < std::min(artwork.sizes.size(), kMaxNumberOfArtworkSizes);
+       ++i)
+    sanitized_artwork.sizes.push_back(artwork.sizes[i]);
+
+  return sanitized_artwork;
+}
+
 }  // namespace content