Use int64_t more consistently for times, in particular for RTT values.

Existing code was inconsistent about whether to use uint16_t, int, unsigned int,
or uint32_t, and sometimes silently truncated one to another, or truncated
int64_t.  Because most core time-handling functions use int64_t, being
consistent about using int64_t unless otherwise necessary minimizes the number
of explicit or implicit casts.

BUG=chromium:81439
TEST=none
R=henrik.lundin@webrtc.org, holmer@google.com, tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/31349004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@8045 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_coding/main/acm2/nack.cc b/webrtc/modules/audio_coding/main/acm2/nack.cc
index 7265fe6..4324cd2 100644
--- a/webrtc/modules/audio_coding/main/acm2/nack.cc
+++ b/webrtc/modules/audio_coding/main/acm2/nack.cc
@@ -207,13 +207,13 @@
   nack_list_.erase(nack_list_.begin(), nack_list_.upper_bound(limit));
 }
 
-int Nack::TimeToPlay(uint32_t timestamp) const {
+int64_t Nack::TimeToPlay(uint32_t timestamp) const {
   uint32_t timestamp_increase = timestamp - timestamp_last_decoded_rtp_;
   return timestamp_increase / sample_rate_khz_;
 }
 
 // We don't erase elements with time-to-play shorter than round-trip-time.
-std::vector<uint16_t> Nack::GetNackList(int round_trip_time_ms) const {
+std::vector<uint16_t> Nack::GetNackList(int64_t round_trip_time_ms) const {
   std::vector<uint16_t> sequence_numbers;
   for (NackList::const_iterator it = nack_list_.begin(); it != nack_list_.end();
       ++it) {