message: Disable BufferSetSubData.ManySetSubData on Metal
  Disables ManySetSubData on Intel/Metal configurations, as it has started
  failing on Mac 10.14.6.
diff: @@ -217,6 +217,9 @@ TEST_P(BufferSetSubDataTests, ManySetSubData) {
  // TODO (jiawei.shao@intel.com): find out why this test fails on Intel Vulkan Linux bots.
  DAWN_SKIP_TEST_IF(IsIntel() && IsVulkan() && IsLinux());
  + // TODO(https://bugs.chromium.org/p/dawn/issues/detail?id=228): Re-enable
  + // once the issue with Metal on 10.14.6 is fixed.
  + DAWN_SKIP_TEST_IF(IsMacOS() && IsIntel() && IsMetal());
  constexpr uint64_t kSize = 4000 * 1000;
  constexpr uint32_t kElements = 500 * 500;
  