cc: Update OWNERS file.

1. Add ajuma@ to the file as an animation owner.
2. Add vollick@ to the layer_tree_host_common/math owners.
3. Add mac-specific stuff to the list of ownership for ccameron@.

R=enne
BUG=

Review URL: https://chromiumcodereview.appspot.com/23904015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222943 0039d316-1c4b-4281-b951-d872f2087c98

cc/OWNERS

@@ -17,7 +17,7 @@ danakj@chromium.org
 piman@chromium.org
 danakj@chromium.org
 
-# resource management
+# resource management / mac-specific
 # unofficial: epenner@chromium.org
 ccameron@chromium.org
 
@@ -36,9 +36,11 @@ vmpstr@chromium.org
 # math / geometry / layer_tree_host_common
 shawnsingh@chromium.org
 enne@chromium.org
+vollick@chromium.org
 
 # animation
 vollick@chromium.org
+ajuma@chromium.org
 
 per-file *.isolate=csharp@chromium.org
 per-file *.isolate=maruel@chromium.org