Switch C++-style C headers with their C equivalents.

The C++ headers define the C functions within the std:: namespace, but
we mainly don't use the std:: namespace for C functions. Therefore we
should include the C headers.

BUG=1833
R=tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1917004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4486 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/video_engine/stream_synchronization.cc b/webrtc/video_engine/stream_synchronization.cc
index 9490d10..fcff782 100644
--- a/webrtc/video_engine/stream_synchronization.cc
+++ b/webrtc/video_engine/stream_synchronization.cc
@@ -10,9 +10,10 @@
 
 #include "webrtc/video_engine/stream_synchronization.h"
 
-#include <algorithm>
 #include <assert.h>
-#include <cmath>
+#include <math.h>
+
+#include <algorithm>
 
 #include "webrtc/system_wrappers/interface/trace.h"