[libcxxabi] Refactor test timing logic and disable by default.

Summary:
When using LIT the timing output is entirely unused but introduces a dependency on `<chrono>`. When libc++ is built without a montonic clock this causes some of the tests to fail.
This patch factors out all of the timing logic into `support/timer.hpp` and disables it by default. To enable the timing you must define `LIBCXXABI_TIME_TESTS`.



Reviewers: mclow.lists, danalbert, jroelofs

Reviewed By: jroelofs

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D6391

llvm-svn: 222701

1 files changed, 2 insertions, 8 deletions

diff --git a/libcxxabi/test/dynamic_cast5.cpp b/libcxxabi/test/dynamic_cast5.cpp
index 89869698c34..d7064f4b4de 100644
--- a/libcxxabi/test/dynamic_cast5.cpp
+++ b/libcxxabi/test/dynamic_cast5.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include <cassert>
+#include "support/timer.hpp"
 
 namespace t1
 {
@@ -1298,15 +1299,10 @@ void test()
 
 }  // t9
 
-#include <chrono>
-#include <iostream>
 
 int main()
 {
-    typedef std::chrono::high_resolution_clock Clock;
-    typedef Clock::time_point time_point;
-    typedef std::chrono::duration<double, std::micro> NS;
-    time_point t0 = Clock::now();
+    timer t;
     t1::test();
     t2::test();
     t3::test();
@@ -1316,6 +1312,4 @@ int main()
     t7::test();
     t8::test();
     t9::test();
-    time_point t1 = Clock::now();
-    std::cout << NS(t1-t0).count() << " microseconds\n";
 }