Added DCHECK() to prevent NULL-pointer dereference

CID=103708
BUG=
TEST=
TBR=tommi

Review URL: https://chromiumcodereview.appspot.com/10834013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@148476 0039d316-1c4b-4281-b951-d872f2087c98

media/audio/win/wavein_input_win.cc

@@ -35,6 +35,7 @@ PCMWaveInAudioInputStream::PCMWaveInAudioInputStream(
       num_buffers_(num_buffers),
       buffer_(NULL),
       channels_(params.channels()) {
+  DCHECK(num_buffers_ > 0);
   format_.wFormatTag = WAVE_FORMAT_PCM;
   format_.nChannels = params.channels() > 2 ? 2 : params.channels();
   format_.nSamplesPerSec = params.sample_rate();