Match existing type usage better.

webrtc/modules/audio_coding/codecs/isac/fix/test/kenny.cc

Index: webrtc/modules/audio_coding/codecs/isac/fix/test/kenny.cc
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/test/kenny.cc b/webrtc/modules/audio_coding/codecs/isac/fix/test/kenny.cc
index ba50b0c678022e72f884f20bc031423a96f2cd15..a3cd2cee6347ad496cf73c4664108f8efab1c20f 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/test/kenny.cc
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/test/kenny.cc
@@ -62,7 +62,8 @@ void get_arrival_time(int current_framesamples,   /* samples */
   /* everything in samples */
   BN_data->sample_count = BN_data->sample_count + current_framesamples;
 
-  BN_data->arrival_time += ((packet_size + HeaderSize) * 8 * FS) / (bottleneck + HeaderRate);
+  BN_data->arrival_time += static_cast<uint32_t>(

[kwiberg-webrtc, 2015/06/08 13:09:38]

checked_cast, so that it will actually fail if out of bounds?

[Peter Kasting, 2015/06/08 20:44:29]

Can this really ever be out-of-bounds in this test?  That seems extraordinarily
unlikely given that the sizes involved should all be very small.

I'm a fan of checked_casts for cases where overflow is in theory possible and
would lead to security problems and other catastrophic issues, but in this case
I don't think it can happen, and if it did, we would simply have some test code
that would get the wrong arrival time in the model, which seems reasonably
benign.

So I'm concerned that using checked_cast misleads the reader into thinking
failure is both more likely and more important here than it really is.

[kwiberg-webrtc, 2015/06/09 00:48:12]

I see your point. dchecked_cast, then? (Yes, I know it doesn't exist yet.)

[Peter Kasting, 2015/06/09 01:18:14]

We could do this if you'd like:

  int arrival_time = ((packet_size + HeaderSize) * 8 * FS) / (bottleneck +
HeaderRate));
  DCHECK(rtc::IsValueInRangeForNumericType<uint32_t>(arrival_time))
  BN_data->arrival_time += static_cast<uint32_t>(arrival_time);

[kwiberg-webrtc, 2015/06/09 01:28:26]

Too much work, and too verbose. It'll only really work well if packaged up as
dchecked_cast or similar.

[Peter Kasting, 2015/06/09 02:10:13]

Hmmm.  I'm not terribly keen on adding something called "dchecked_cast" as it
sounds as if it happens in the same scenarios DCHECK is on, when in fact the
cast happens all the time.

If you're really super-keen on this I could ask the security folks that put in
checked_cast what they think.  Personally I'm inclined to leave this one as the
static_cast.

[kwiberg-webrtc, 2015/06/09 10:56:31]

I would have thought it was obvious---there's only one reasonable
thing it could do, and casting or not depending on DCHECK_IS_ON isn't
one of them. But then I thought of the name, so I would say that...
I guess you can leave it. But this isn't the first time I've wanted
dchecked_cast, so chances are I'll get around to building it one of
these days.

[Peter Kasting, 2015/06/10 01:09:54]

Acknowledged.

+      ((packet_size + HeaderSize) * 8 * FS) / (bottleneck + HeaderRate));
   BN_data->send_time += current_framesamples;
 
   if (BN_data->arrival_time < BN_data->sample_count)