Fix arrow placement on menulist with padding

The arrow calculation does not take padding into account, so it is
"underneath" the padding if >1.

BUG=586127
[email protected]
TEST=Have run the /fast/form tests, and nothing reverts except items which are fixed by this change.

Review-Url: https://codereview.chromium.org/1931273003
Cr-Commit-Position: refs/heads/master@{#392008}
diff --git a/AUTHORS b/AUTHORS
index 614b2a1..ff2be5f 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -14,6 +14,7 @@
 Abhijeet Kandalkar <[email protected]>
 Abhishek Agarwal <[email protected]>
 Abhishek Singh <[email protected]>
+Adam Bonner <[email protected]>
 Adam Roben <[email protected]>
 Adam Treat <[email protected]>
 Addanki Gandhi Kishor <[email protected]>