clock.h: Removed GUARDED_BY annotation as it breaks som builds.

BUG=N/A
TBR=henrik.lundin@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/14769004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6547 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/system_wrappers/interface/clock.h b/webrtc/system_wrappers/interface/clock.h
index 2bb6c10..ed65006 100644
--- a/webrtc/system_wrappers/interface/clock.h
+++ b/webrtc/system_wrappers/interface/clock.h
@@ -13,7 +13,6 @@
 
 #include "webrtc/system_wrappers/interface/rw_lock_wrapper.h"
 #include "webrtc/system_wrappers/interface/scoped_ptr.h"
-#include "webrtc/system_wrappers/interface/thread_annotations.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
@@ -77,7 +76,7 @@
   void AdvanceTimeMicroseconds(int64_t microseconds);
 
  private:
-  int64_t time_us_ GUARDED_BY(lock_);
+  int64_t time_us_;
   scoped_ptr<RWLockWrapper> lock_;
 };