Moved DCHECK() to prevent NULL deref of codec_context_.

media/filters/audio_file_reader.cc

Index: media/filters/audio_file_reader.cc
diff --git a/media/filters/audio_file_reader.cc b/media/filters/audio_file_reader.cc
index 706a9aac45b727c18c7639b7905e7543a68c102a..ccfafa101a4957702e9595828dbbd3c6f723c465 100644
--- a/media/filters/audio_file_reader.cc
+++ b/media/filters/audio_file_reader.cc
@@ -112,17 +112,14 @@ void AudioFileReader::Close() {
 
 bool AudioFileReader::Read(const std::vector<float*>& audio_data,
                            size_t number_of_frames) {
+  DCHECK(format_context_ && codec_context_ && codec_) <<
+      "AudioFileReader::Read() : reader is not opened!";
+
   size_t channels = this->channels();
   DCHECK_EQ(audio_data.size(), channels);
   if (audio_data.size() != channels)
     return false;
 
-  DCHECK(format_context_ && codec_context_ && codec_);
-  if (!format_context_ || !codec_context_ || !codec_) {
-    DLOG(WARNING) << "AudioFileReader::Read() : reader is not opened!";
-    return false;
-  }
-
   // Holds decoded audio.
   scoped_ptr_malloc<AVFrame, ScopedPtrAVFree> av_frame(avcodec_alloc_frame());