Revert of Pass initDataType instead of contentType on OnNeedKey().

content/renderer/media/android/webmediaplayer_android.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/android/webmediaplayer_android.h"
 
 #include <limits>
 
 #include "base/android/build_info.h"
 #include "base/bind.h"
@@ skipping 1465 matching lines @@
   WebMediaPlayer::MediaKeyException e =
       GenerateKeyRequestInternal(ascii_key_system, init_data, init_data_length);
   ReportMediaKeyExceptionToUMA("generateKeyRequest", ascii_key_system, e);
   return e;
 }
 
 // Guess the type of |init_data|. This is only used to handle some corner cases
 // so we keep it as simple as possible without breaking major use cases.
 static std::string GuessInitDataType(const unsigned char* init_data,
                                      unsigned init_data_length) {
-  // Most WebM files use KeyId of 16 bytes. CENC init data is always >16 bytes.
+  // Most WebM files use KeyId of 16 bytes. MP4 init data are always >16 bytes.
   if (init_data_length == 16)
-    return "webm";
+    return "video/webm";
 
-  return "cenc";
+  return "video/mp4";
 }
 
 // TODO(xhwang): Report an error when there is encrypted stream but EME is
 // not enabled. Currently the player just doesn't start and waits for
 // ever.
 WebMediaPlayer::MediaKeyException
 WebMediaPlayerAndroid::GenerateKeyRequestInternal(
     const std::string& key_system,
     const unsigned char* init_data,
     unsigned init_data_length) {
@@ skipping 313 matching lines @@
 
 bool WebMediaPlayerAndroid::IsHLSStream() const {
   std::string mime;
   GURL url = redirected_url_.is_empty() ? url_ : redirected_url_;
   if (!net::GetMimeTypeFromFile(base::FilePath(url.path()), &mime))
     return false;
   return !mime.compare("application/x-mpegurl");
 }
 
 }  // namespace content