Enable video in linux build and remove unneeded ifdefs to guard windows.

media/filters/ffmpeg_audio_decoder.cc

 // Copyright (c) 2009 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/base/data_buffer.h"
 #include "media/filters/ffmpeg_audio_decoder.h"
 #include "media/filters/ffmpeg_common.h"
 #include "media/filters/ffmpeg_demuxer.h"
 
 namespace media {
@@ skipping 59 matching lines @@
 
 void FFmpegAudioDecoder::OnDecode(Buffer* input) {
   int16_t* output_buffer = reinterpret_cast<int16_t*>(output_buffer_.get());
   int output_buffer_size = kOutputBufferSize;
   int result = avcodec_decode_audio2(codec_context_,
                                      output_buffer,
                                      &output_buffer_size,
                                      input->GetData(),
                                      input->GetDataSize());
 
-  if (result < 0 || output_buffer_size > kOutputBufferSize) {
+  // TODO(ajwong): Consider if kOutputBufferSize should just be an int instead
+  // of a size_t.
+  if (result < 0 ||
+      output_buffer_size < 0 ||
+      static_cast<size_t>(output_buffer_size) > kOutputBufferSize) {
     host_->Error(PIPELINE_ERROR_DECODE);
   } else if (result == 0) {
     // TODO(scherkus): does this mark EOS? Do we want to fulfill a read request
     // with zero size?
   } else {
     DataBuffer* result_buffer = new DataBuffer();
     memcpy(result_buffer->GetWritableData(output_buffer_size),
            output_buffer, output_buffer_size);
     result_buffer->SetTimestamp(input->GetTimestamp());
     result_buffer->SetDuration(input->GetDuration());
     EnqueueResult(result_buffer);
   }
 }
 
 }  // namespace