Compilation fix for wxStopWatch with wxUSE_THREADS==0.

Use wxCRIT_SECT_DECLARE_MEMBER/wxCRIT_SECT_LOCKER macros which expand to
nothing in wxUSE_THREADS==0 case instead of using wxCriticalSection[Locker]
classes which are not defined then.

Also explicitly include wx/thread.h.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70012 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/stopwatch.cpp

@@ -37,6 +37,7 @@
         #include "wx/msw/wrapwin.h"
     #endif
     #include "wx/log.h"
+    #include "wx/thread.h"
 #endif //WX_PRECOMP
 
 // ============================================================================
@@ -64,7 +65,7 @@ struct PerfCounter
         return freq.QuadPart != 0;
     }
 
-    wxCriticalSection cs;
+    wxCRIT_SECT_DECLARE_MEMBER(cs);
     LARGE_INTEGER freq;
     bool init;
 } gs_perfCounter;
@@ -82,7 +83,7 @@ void wxStopWatch::DoStart()
 #ifdef __WXMSW__
     if ( !gs_perfCounter.init )
     {
-        wxCriticalSectionLocker lock(gs_perfCounter.cs);
+        wxCRIT_SECT_LOCKER(lock, gs_perfCounter.cs);
         ::QueryPerformanceFrequency(&gs_perfCounter.freq);
 
         // Just a sanity check: it's not supposed to happen but verify that