Adding check for MIME types that do not take codecs parameter

content/renderer/renderer_webkitplatformsupport_impl.cc

 // Copyright (c) 2012 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/renderer_webkitplatformsupport_impl.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/lazy_instance.h"
 #include "base/memory/shared_memory.h"
@@ skipping 414 matching lines @@
     if (!IsSupportedKeySystemWithMediaMimeType(
             mime_type_ascii, strict_codecs, key_system_ascii)) {
       return IsNotSupported;
     }
 
     // Continue processing the mime_type and codecs.
   }
 
   // Check list of strict codecs to see if it is supported.
   if (net::IsStrictMediaMimeType(mime_type_ascii)) {
+    // Check if the codecs are a perfect match.
+    std::vector<std::string> strict_codecs;
+    net::ParseCodecString(ToASCIIOrEmpty(codecs), &strict_codecs, false);
+    if (net::IsSupportedStrictMediaMimeType(mime_type_ascii, strict_codecs))

[Ryan Sleevi, 2014/04/18 01:57:41]

How does this work without you also requiring to change AreSupportedCodecs?

ParseCodecString results in an empty strict_codecs

net::IsSupportedStrictMediaMimeType finds "audio/mp3" within strict_format_map_,
so it calls AreSupportedCodecs(), with the first parameter as an empty vector
(as no supported codecs) and the second parameter as an empty vector (as it's
the above strict_codecs parameter)

AreSupportedCodecs() iterates through codecs (empty) to see if any of them are
within supported_codecs - but this is a no-op. As a result, it hits the final
condition - "return !codecs.empty()". However, codecs.empty() == true,
!codecs.empty() == false, therefore AreSupportedCodecs() should return false, so
shouldn't we be hidding line 441-443?

Have you tested this code? Am I missing something? Is it creating a codecs_out
with an empty string instead of an empty vector?

[amogh.bihani, 2014/04/21 06:10:56]

I'm sorry I missed this. I did test this code. The testcases were passing. But
they were passing because USE_PROPRIETARY_CODECS was not enabled in my system.

We cannot remove lines 441 to 443 as "maybe" is a valid response and we need to
give this when no codecs are present for the containers which expect 'codecs'
parameter.

+      return IsSupported;
+
     // We support the container, but no codecs were specified.
     if (codecs.isNull())
       return MayBeSupported;
 
-    // Check if the codecs are a perfect match.
-    std::vector<std::string> strict_codecs;
-    net::ParseCodecString(ToASCIIOrEmpty(codecs), &strict_codecs, false);
-    if (!net::IsSupportedStrictMediaMimeType(mime_type_ascii, strict_codecs))
-      return IsNotSupported;
-
-    // Good to go!
-    return IsSupported;
+    return IsNotSupported;
   }
 
   // If we don't recognize the codec, it's possible we support it.
   std::vector<std::string> parsed_codecs;
   net::ParseCodecString(ToASCIIOrEmpty(codecs), &parsed_codecs, true);
   if (!net::AreSupportedMediaCodecs(parsed_codecs))
     return MayBeSupported;
 
   // Otherwise we have a perfect match.
   return IsSupported;
@@ skipping 716 matching lines @@
     return;
   QuotaDispatcher::ThreadSpecificInstance(
       thread_safe_sender_.get(),
       quota_message_filter_.get())->QueryStorageUsageAndQuota(
           storage_partition,
           static_cast<quota::StorageType>(type),
           QuotaDispatcher::CreateWebStorageQuotaCallbacksWrapper(callbacks));
 }
 
 }  // namespace content