Replace basictypes.h with stdint.h for int_t types.

Removes basictypes.h for types that only makes use of it for fixed-size-int
typedefs and replaces it with stdint.h.

BUG=webrtc:6853
R=tommi@webrtc.org

Review-Url: https://codereview.webrtc.org/2604043002
Cr-Commit-Position: refs/heads/master@{#15867}

webrtc/modules/rtp_rtcp/source/time_util.h

@@ -11,7 +11,8 @@
 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_TIME_UTIL_H_
 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_TIME_UTIL_H_
 
-#include "webrtc/base/basictypes.h"
+#include <stdint.h>
+
 #include "webrtc/system_wrappers/include/ntp_time.h"
 
 namespace webrtc {