Change default timestamp to 64 bits in all webrtc directories.

BUG=
R=pbos@webrtc.org, pthatcher@webrtc.org, solenberg@webrtc.org

Review URL: https://codereview.webrtc.org/1835053002 .

Cr-Original-Commit-Position: refs/heads/master@{#12646}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 82d7862fe736f851ea1cf28e8b2ce9fa6be37e45
diff --git a/pc/currentspeakermonitor.h b/pc/currentspeakermonitor.h
index 19a61f9..730ded0 100644
--- a/pc/currentspeakermonitor.h
+++ b/pc/currentspeakermonitor.h
@@ -54,7 +54,7 @@
   // Used by tests.  Note that the actual minimum time between switches
   // enforced by the monitor will be the given value plus or minus the
   // resolution of the system clock.
-  void set_min_time_between_switches(uint32_t min_time_between_switches);
+  void set_min_time_between_switches(int min_time_between_switches);
 
   // This is fired when the current speaker changes, and provides his audio
   // SSRC.  This only fires after the audio monitor on the underlying
@@ -86,8 +86,8 @@
   uint32_t current_speaker_ssrc_;
   // To prevent overswitching, switching is disabled for some time after a
   // switch is made.  This gives us the earliest time a switch is permitted.
-  uint32_t earliest_permitted_switch_time_;
-  uint32_t min_time_between_switches_;
+  int64_t earliest_permitted_switch_time_;
+  int min_time_between_switches_;
 };
 
 }  // namespace cricket