Update PluginInstance for audio support for content decryption.

media/filters/decrypting_audio_decoder.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 "media/filters/decrypting_audio_decoder.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/message_loop_proxy.h"
@@ skipping 179 matching lines @@
   DCHECK(!read_cb.is_null());
   CHECK(read_cb_.is_null()) << "Overlapping decodes are not supported.";
 
   // Return empty (end-of-stream) frames if decoding has finished.
   if (state_ == kDecodeFinished) {
     read_cb.Run(kOk, scoped_refptr<Buffer>(new DataBuffer(0)));
     return;
   }
 
   if (!queued_audio_frames_.empty()) {
-    if (queued_audio_frames_.front()->IsEndOfStream())
-      state_ = kDecodeFinished;
+    DCHECK(!queued_audio_frames_.front()->IsEndOfStream());
+    DCHECK_GT(queued_audio_frames_.front()->GetDataSize(), 0);
     read_cb.Run(kOk, queued_audio_frames_.front());
     queued_audio_frames_.pop_front();
     return;
   }
 
   read_cb_ = read_cb;
   state_ = kPendingDemuxerRead;
   ReadFromDemuxerStream();
 }
 
@@ skipping 149 matching lines @@
   }
 
   DCHECK_EQ(status, Decryptor::kSuccess);
   queued_audio_frames_ = frames;
 
   scoped_refptr<Buffer> first_frame = queued_audio_frames_.front();
   queued_audio_frames_.pop_front();
   // No frames returned in the list should be an end-of-stream (EOS) frame.
   // EOS frame should be returned separately as (kNeedMoreData, NULL).
   DCHECK(!first_frame->IsEndOfStream());
+  DCHECK_GT(first_frame->GetDataSize(), 0);
   state_ = kIdle;
   base::ResetAndReturn(&read_cb_).Run(kOk, first_frame);
 }
 
 void DecryptingAudioDecoder::OnKeyAdded() {
   DCHECK(message_loop_->BelongsToCurrentThread());
 
   if (state_ == kPendingDecode) {
     key_added_while_pending_decode_ = true;
     return;
   }
 
   if (state_ == kWaitingForKey) {
     state_ = kPendingDecode;
     DecodePendingBuffer();
   }
 }
 
 void DecryptingAudioDecoder::DoReset() {
   DCHECK(init_cb_.is_null());
   DCHECK(read_cb_.is_null());
   state_ = kIdle;
   base::ResetAndReturn(&reset_cb_).Run();
 }
 
 }  // namespace media