Remove usages of XInternAtom

PRESUBMIT.py

Index: PRESUBMIT.py
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 8a81bb0babc1d3961b1dfea2fa5894d6ce306bad..64dad0d7f7347a5e4eb59490d864e419cc77ab12 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -189,6 +189,17 @@ _BANNED_CPP_FUNCTIONS = (
       ),
     ),
     (
+      r'XInternAtom|xcb_intern_atom',
+      (
+       'Use ui::GetAtom() or ui::X11AtomCache::GetAtom() instead of',

[sadrul, 2017/06/01 20:45:30]

Can we actually remove one of them? e.g. just gfx::GetAtom()

[Tom Anderson, 2017/06/01 21:20:42]

We need at least ui::X11AtomCache::GetAtom() because some things at a lower
level than ui (like gfx) need to get atoms too.  I don't think it hurts having
ui::GetAtom that wraps "ui::X11AtomCache::GetInstance()->GetAtom()".  wdyt?

[sadrul, 2017/06/07 17:32:40]

That's why I was suggesting a gfx::GetAtom(), so that code that does depend on
ui can still use it.

Having one way of doing the same thing is better than having two ways. So unless
there's a non-trivial amount of existing use of both functions now, I would
suggest removing one. (can be separate CL though)

+       'interning atoms directly.',
+      ),
+      True,
+      (
+        r"^ui[\\\/]gfx[\\\/]x[\\\/]x11_atom_cache\.cc$",
+      ),
+    ),
+    (
       'ScopedAllowIO',
       (
        'New code should not use ScopedAllowIO. Post a task to the blocking',