Rebase webrtc/base 6163:6216 (svn diff -r 6163:6216 http://webrtc.googlecode.com/svn/trunk/talk/base, apply diff manually)

BUG=3379
TBR=wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/17619004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6217 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/base/timeutils.h b/webrtc/base/timeutils.h
index bdf73cc..ca041a7 100644
--- a/webrtc/base/timeutils.h
+++ b/webrtc/base/timeutils.h
@@ -80,6 +80,17 @@
   return unix_ts_ns / kNumNanosecsPerMillisec + kJan1970AsNtpMillisecs;
 }
 
+class TimestampWrapAroundHandler {
+ public:
+  TimestampWrapAroundHandler();
+
+  int64 Unwrap(uint32 ts);
+
+ private:
+  uint32 last_ts_;
+  int64 num_wrap_;
+};
+
 }  // namespace rtc
 
 #endif  // WEBRTC_BASE_TIMEUTILS_H_