Only use ATK_XY_PARENT if atk is new enough

ATK_XY_PARENT was added in atk 2.30 so attempts to use it
with earlier versions will not compile.

Bug: 934274
Change-Id: I27a2f9a72c7977300860b7442d9ee4b53f0c1f62
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1530913
Commit-Queue: Daniel Bratell <bratell@opera.com>
Reviewed-by: Martin Robinson <mrobinson@igalia.com>
Cr-Commit-Position: refs/heads/master@{#642630}
2 files changed