Simplify skiatest framework.

skiatest::Test class is now a simple struct.  Some
functionalty, such as counting errors or timing is now
handled elsewhere.

skiatest:Reporter is now a simpler abstract class.  The two
implementations handle test errors.

DM and pathops_unittest updated.

Review URL: https://codereview.chromium.org/830513004
diff --git a/tests/MetaDataTest.cpp b/tests/MetaDataTest.cpp
index 8ed1e49..9d8d5dd 100644
--- a/tests/MetaDataTest.cpp
+++ b/tests/MetaDataTest.cpp
@@ -7,6 +7,7 @@
 
 #include "SkMetaData.h"
 #include "Test.h"
+#include "SkRefCnt.h"
 
 static void test_ptrs(skiatest::Reporter* reporter) {
     SkRefCnt ref;