Fix: Adding list of supported codecs for MP4 containers

net/base/mime_util.h

Index: net/base/mime_util.h
diff --git a/net/base/mime_util.h b/net/base/mime_util.h
index 6c943a7f7da83dc1f1e021c6db4578bfe7188621..24c4414342a29cb9c631badd6791e95779a227d3 100644
--- a/net/base/mime_util.h
+++ b/net/base/mime_util.h
@@ -94,12 +94,33 @@ NET_EXPORT void ParseCodecString(const std::string& codecs,
 // certain subset of codecs.
 NET_EXPORT bool IsStrictMediaMimeType(const std::string& mime_type);
 
-// Check to see if a particular MIME type is in our list which only supports a
-// certain subset of codecs. Returns true if and only if all codecs are
-// supported for that specific MIME type, false otherwise. If this returns
-// false you will still need to check if the media MIME tpyes and codecs are
-// supported.
-NET_EXPORT bool IsSupportedStrictMediaMimeType(
+// Indicates that the MIME type and (possible codec string) are supported by the
+// underlying platform.
+// IsNotSupported - The underlying platform is known not to support the given
+//                  MIME type and codec combination.
+// IsSuported     - The underlying platform is known to support the given MIME
+//                  type and codec combination.
+// MayBeSupported - The underlying platform is unsure whether the given MIME
+//                  type and codec combination can be rendered or not before
+//                  actually trying to play it.

[Ryan Sleevi, 2014/06/12 19:03:53]

Document these inline, as suggested

// Comment describing SupportsType
enum SupportsType {
  // Comment describing IsNotSupported
  IsNotSupported,

  // Comment describing IsSupported
  IsSupported,

  // Comment describing MayBeSupported
  MayBeSupported
};

+enum SupportsType {
+  IsNotSupported,
+  IsSupported,
+  MayBeSupported
+};
+
+// Checks the |mime_type| and |codecs| against the MIME types known to support
+// only a particular subset of codecs.
+// * Returns IsSupported if the |mime_type| is supported and all the codecs
+//   within the |codecs| are supported for the |mime_type|.
+// * Returns MayBeSupported if the |mime_type| is supported and is known to
+//   support only a subset of codecs, but |codecs| was empty. Also returned if a
+//   codec is supported, but additional codec parameters were supplied (such as
+//   profile) for which the support cannot be decided.

[Ryan Sleevi, 2014/06/12 19:03:53]

Still doesn't document what happens in the case of

codecs { A, B.UnsupportedProfile, C }

where A is supported, B MAY be supported, and C is not supported.

Suggested resolution:

"Also returned if all of the codecs listed in |codec| are supported, but
additional codec parameters were supplied (such as a profile) for which support
cannot be decided"

+// * Returns IsNotSupported if either the |mime_type| is not supported or the
+//   |mime_type| is supported but atleast one of the codecs within |codecs| is

[Ryan Sleevi, 2014/06/12 19:03:53]

s/atleast/at least/

+//   not supported for the |mime_type|.
+NET_EXPORT SupportsType IsSupportedStrictMediaMimeType(
     const std::string& mime_type,
     const std::vector<std::string>& codecs);