Change default timestamp to 64 bits in all webrtc directories.

webrtc/base/thread.cc

Index: webrtc/base/thread.cc
diff --git a/webrtc/base/thread.cc b/webrtc/base/thread.cc
index dc8ccdfd4dd1dafd958f487450e254bb7b901693..019a1ce105af7eca8bb54a725aacc29e80837fe7 100644
--- a/webrtc/base/thread.cc
+++ b/webrtc/base/thread.cc
@@ -459,7 +459,7 @@ void Thread::Clear(MessageHandler* phandler,
 }
 
 bool Thread::ProcessMessages(int cmsLoop) {
-  uint32_t msEnd = (kForever == cmsLoop) ? 0 : TimeAfter(cmsLoop);
+  int64_t msEnd = (kForever == cmsLoop) ? 0 : TimeAfter(cmsLoop);
   int cmsNext = cmsLoop;
 
   while (true) {