Implement MediaSource support for mojo.

- Implements WebMimeRegistryImpl::supportsMediaSourceMIMEType().
- Changes NullEncryptedMediaPlayerSupport to return a callback
  bound to NOTIMPLEMENTED() for the NeedKeyCB.

BUG=423416
TEST=basic mse player plays!

Review URL: https://codereview.chromium.org/653213002

Cr-Commit-Position: refs/heads/master@{#300012}

media/blink/null_encrypted_media_player_support.cc

@@ -4,11 +4,17 @@
 
 #include "media/blink/null_encrypted_media_player_support.h"
 
+#include "base/bind.h"
 #include "third_party/WebKit/public/platform/WebContentDecryptionModule.h"
 #include "third_party/WebKit/public/platform/WebContentDecryptionModuleResult.h"
 
 namespace media {
 
+static void NeedKeyHandler(const std::string& type,
+                           const std::vector<uint8>& init_data) {
+  NOTIMPLEMENTED();
+}
+
 scoped_ptr<EncryptedMediaPlayerSupport>
 NullEncryptedMediaPlayerSupport::Create(blink::WebMediaPlayerClient* client) {
   return scoped_ptr<EncryptedMediaPlayerSupport>(
@@ -66,7 +72,7 @@ void NullEncryptedMediaPlayerSupport::SetContentDecryptionModule(
 }
 
 Demuxer::NeedKeyCB NullEncryptedMediaPlayerSupport::CreateNeedKeyCB() {
-  return Demuxer::NeedKeyCB();
+  return base::Bind(&NeedKeyHandler);
 }
 
 SetDecryptorReadyCB

mojo/services/html_viewer/webmimeregistry_impl.cc

@@ -8,6 +8,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
+#include "media/filters/stream_parser_factory.h"
 #include "net/base/mime_util.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 
@@ -89,8 +90,14 @@ blink::WebMimeRegistry::SupportsType WebMimeRegistryImpl::supportsMediaMIMEType(
 bool WebMimeRegistryImpl::supportsMediaSourceMIMEType(
     const blink::WebString& mime_type,
     const blink::WebString& codecs) {
-  NOTIMPLEMENTED();
-  return false;
+  const std::string mime_type_ascii = ToASCIIOrEmpty(mime_type);
+  if (mime_type_ascii.empty())
+    return false;
+
+  std::vector<std::string> parsed_codec_ids;
+  net::ParseCodecString(ToASCIIOrEmpty(codecs), &parsed_codec_ids, false);
+  return media::StreamParserFactory::IsTypeSupported(mime_type_ascii,
+                                                     parsed_codec_ids);
 }
 
 bool WebMimeRegistryImpl::supportsEncryptedMediaMIMEType(