mac: Remove vestiges of 32-bit deprecation

32-bit support was dropped in Chrome 39, a year ago. It seems like a
good time to stop carrying this stuff around.

Review URL: https://codereview.chromium.org/1438313003

Cr-Original-Commit-Position: refs/heads/master@{#360153}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: c5af6de2b6499645244d173f841b4013f3c60a56

mac/tweak_info_plist.py

@@ -159,7 +159,7 @@ def _RemoveBreakpadKeys(plist):
 def _TagSuffixes():
   # Keep this list sorted in the order that tag suffix components are to
   # appear in a tag value. That is to say, it should be sorted per ASCII.
-  components = ('32bit', 'full')
+  components = ('full',)
   assert tuple(sorted(components)) == components
 
   components_len = len(components)