Change the win, mac, and linux trybots to build Release.

build/masters/master.tryserver.chromium/slaves.cfg

Index: build/masters/master.tryserver.chromium/slaves.cfg
===================================================================
--- build/masters/master.tryserver.chromium/slaves.cfg	(revision 102013)
+++ build/masters/master.tryserver.chromium/slaves.cfg	(working copy)
@@ -17,7 +17,7 @@
   # Configurations on every VM.
   base = [
       # One line per shared directory. In decreasing usage:
-      'linux', 'linux_rel', 'linux_sync',
+      'linux', 'linux_dbg', 'linux_sync',
       'linux_clang',
       'linux_chromeos',
   ]
@@ -69,7 +69,7 @@
       'master': 'TryServer',
       'builder': [
           # One line per shared directory:
-          'mac', 'mac_rel', 'mac_sync',
+          'mac', 'mac_dbg', 'mac_sync',
           'mac_layout', 'mac_layout_rel',
           'mac_valgrind',
           'mac_clang_no_goma',
@@ -89,7 +89,7 @@
   return [
     {
       'master': 'TryServer',
-      'builder': ['win', 'win_rel', 'win_sync', 'win_shared'],
+      'builder': ['win', 'win_dbg', 'win_sync', 'win_shared'],
       'hostname': 'vm%d-m4' % i,
       'os': 'win',
       'version': 'vista',