Add ART -help and -showversion

Bug: https://code.google.com/p/android/issues/detail?id=62149
Change-Id: I5c21c0433f5f341f94e7d977e8d2d69cc46d6fe3
diff --git a/runtime/trace.cc b/runtime/trace.cc
index 18185d4..1f24478 100644
--- a/runtime/trace.cc
+++ b/runtime/trace.cc
@@ -115,11 +115,7 @@
 static const uint16_t kTraceRecordSizeSingleClock = 10;  // using v2
 static const uint16_t kTraceRecordSizeDualClock   = 14;  // using v3 with two timestamps
 
-#if defined(HAVE_POSIX_CLOCKS)
-ProfilerClockSource Trace::default_clock_source_ = kProfilerClockSourceDual;
-#else
-ProfilerClockSource Trace::default_clock_source_ = kProfilerClockSourceWall;
-#endif
+ProfilerClockSource Trace::default_clock_source_ = kDefaultProfilerClockSource;
 
 Trace* volatile Trace::the_trace_ = NULL;
 pthread_t Trace::sampling_pthread_ = 0U;