Define HAS_FEATURE instead of __has_feature

As discussed in: https://codereview.chromium.org/1837563002/

The approach is what's recommended by clang and is safe because __has_feature
was only defined if the compiler didn't provide it, but nonetheless it's good to
be consistent.

R=thakis@chromium.org

Review URL: https://codereview.chromium.org/1866473002

Cr-Commit-Position: refs/heads/master@{#385541}


CrOS-Libchrome-Original-Commit: a8dc9dd8ca283435a6a312918f0526300c91e8de
2 files changed
tree: 1cd1c953bda72e04b0410bfb3ce2c9cecf91cc23
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/