Suppress ProvokingVertexTest.FlatTriWithTransformFeedback on Mac AMD

BUG=

Change-Id: Ia6e7c67aaed40cca70be5522e0b9edff2610b63a
Reviewed-on: https://chromium-review.googlesource.com/322212
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Corentin Wallez <cwallez@chromium.org>
Tryjob-Request: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/tests/gl_tests/ProvokingVertexTest.cpp b/src/tests/gl_tests/ProvokingVertexTest.cpp
index ff4564b..07db501 100644
--- a/src/tests/gl_tests/ProvokingVertexTest.cpp
+++ b/src/tests/gl_tests/ProvokingVertexTest.cpp
@@ -140,6 +140,15 @@
 // Ensure that any provoking vertex shenanigans still gives correct vertex streams.
 TEST_P(ProvokingVertexTest, FlatTriWithTransformFeedback)
 {
+    // TODO(cwallez) figure out why it is broken on AMD on Mac
+#if defined(ANGLE_PLATFORM_APPLE)
+    if (isAMD())
+    {
+        std::cout << "Test skipped on AMD on Mac." << std::endl;
+        return;
+    }
+#endif
+
     glGenTransformFeedbacks(1, &mTransformFeedback);
     glBindTransformFeedback(GL_TRANSFORM_FEEDBACK, mTransformFeedback);