KeySystems: IsSupportedContainerAndCodecs() ignores empty codec.

content/renderer/media/crypto/key_systems.cc

 // Copyright 2013 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.
 
 #include "content/renderer/media/crypto/key_systems.h"
 
 #include <string>
 
 #include "base/containers/hash_tables.h"
 #include "base/lazy_instance.h"
@@ skipping 263 matching lines @@
   DCHECK(!container.empty());
   DCHECK(!codecs.empty());
   DCHECK(IsSupportedContainer(container, key_system_supported_codecs));
 
   CodecMaskMap::const_iterator container_iter =
       container_codec_masks_.find(container);
   EmeCodec container_codec_mask = container_iter->second;
 
   for (size_t i = 0; i < codecs.size(); ++i) {
     const std::string& codec = codecs[i];
-    DCHECK(!codec.empty());
+    if (codec.empty())

[ddorwin, 2014/04/26 00:51:36]

Does this cause use to accept a real string like "foo, , bar" or "foo,"? I
wonder whether we should.

Does canPlayType()?

+      continue;
     CodecMaskMap::const_iterator codec_iter = codec_masks_.find(codec);
     if (codec_iter == codec_masks_.end())  // Unrecognized codec.
       return false;
 
     EmeCodec codec_mask = codec_iter->second;
     if (!(codec_mask & key_system_supported_codecs))  // Unsupported codec.
       return false;
 
     // Unsupported codec/container combination, e.g. "video/webm" and "avc1".
     if (!(codec_mask & container_codec_mask))
@@ skipping 149 matching lines @@
 CONTENT_EXPORT void AddContainerMask(const std::string& container,
                                      uint32 mask) {
   KeySystems::GetInstance().AddContainerMask(container, mask);
 }
 
 CONTENT_EXPORT void AddCodecMask(const std::string& codec, uint32 mask) {
   KeySystems::GetInstance().AddCodecMask(codec, mask);
 }
 
 }  // namespace content