CTest: adopt std::chrono::system_clock

After the refactor to make CTest use std::chrono::steady_clock for the
keeping of time for test duration, there are still references to
cmSystemTools::GetTime() left.
To further adopt std::chrono for time related activities, this commit
changes those remaining references to std::chrono::system_clock::now()
calls and alters the storage from either unsigned int or double to
std::chrono::system_clock::time_point.

For ease of conversion, a converter method is added to cmXMLWriter that
converts from a std::chrono::system_clock::time_point to the number of
seconds since the UN*X epoch as that is expected behaviour. This means
no more casts as required.

Functionally should be no difference as the system_clock is implemented
in the same terms.

1 files changed, 2 insertions, 2 deletions

diff --git a/Source/CTest/cmCTestTestHandler.h b/Source/CTest/cmCTestTestHandler.h
index af85e72..8572e7b 100644
--- a/Source/CTest/cmCTestTestHandler.h
+++ b/Source/CTest/cmCTestTestHandler.h
@@ -207,8 +207,8 @@ protected:
   std::vector<std::string> CustomTestsIgnore;
   std::string StartTest;
   std::string EndTest;
-  unsigned int StartTestTime;
-  unsigned int EndTestTime;
+  std::chrono::system_clock::time_point StartTestTime;
+  std::chrono::system_clock::time_point EndTestTime;
   bool MemCheck;
   int CustomMaximumPassedTestOutputSize;
   int CustomMaximumFailedTestOutputSize;