harden and speed up path op unit tests

tests/PathOpsDPointTest.cpp

Index: tests/PathOpsDPointTest.cpp
diff --git a/tests/PathOpsDPointTest.cpp b/tests/PathOpsDPointTest.cpp
index 688d01b890bb34e5e9bd58b6358629b38a9f9822..8621e66798ce137fbe7b863d266d0eec7289a68f 100644
--- a/tests/PathOpsDPointTest.cpp
+++ b/tests/PathOpsDPointTest.cpp
@@ -4,6 +4,7 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+#include "PathOpsTestCommon.h"
 #include "SkPathOpsPoint.h"
 #include "Test.h"
 
@@ -22,6 +23,7 @@ static const size_t tests_count = SK_ARRAY_COUNT(tests);
 static void PathOpsDPointTest(skiatest::Reporter* reporter) {
     for (size_t index = 0; index < tests_count; ++index) {
         const SkDPoint& pt = tests[index];
+        SkASSERT(ValidPoint(pt));
         SkDPoint p = pt;
         REPORTER_ASSERT(reporter, p == pt);
         REPORTER_ASSERT(reporter, !(pt != pt));