Test to try to track down the alignment problem on Mac 10.9.
There's no code change here, I'm rearranging member variables of the
trace class and adding a sizeof check to the CriticalSection
class + alignment attribute for the mutex, on Mac only.

TBR=pbos@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/38339004

Cr-Commit-Position: refs/heads/master@{#8540}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8540 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/system_wrappers/source/trace_impl.h b/webrtc/system_wrappers/source/trace_impl.h
index 62223da..da5af72 100644
--- a/webrtc/system_wrappers/source/trace_impl.h
+++ b/webrtc/system_wrappers/source/trace_impl.h
@@ -93,12 +93,12 @@
   void WriteToFile(const char* msg, uint16_t length)
       EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
-  rtc::CriticalSection crit_;
   TraceCallback* callback_ GUARDED_BY(crit_);
   uint32_t row_count_text_ GUARDED_BY(crit_);
   uint32_t file_count_text_ GUARDED_BY(crit_);
 
   const rtc::scoped_ptr<FileWrapper> trace_file_ GUARDED_BY(crit_);
+  rtc::CriticalSection crit_;
 };
 
 }  // namespace webrtc