Bring back baremetal trybots to the default set.

tools/autoroller/roll_chromium_revision.py

Index: tools/autoroller/roll_chromium_revision.py
diff --git a/tools/autoroller/roll_chromium_revision.py b/tools/autoroller/roll_chromium_revision.py
index 56d878ac9b52f3f99753391029906531d54af71c..1f974e02ef72b7bbfed2a74e8af6e5658c6b6bb7 100755
--- a/tools/autoroller/roll_chromium_revision.py
+++ b/tools/autoroller/roll_chromium_revision.py
@@ -25,9 +25,6 @@ CHROMIUM_COMMIT_TEMPLATE = CHROMIUM_SRC_URL + '/+/%s'
 CHROMIUM_LOG_TEMPLATE = CHROMIUM_SRC_URL + '/+log/%s'
 CHROMIUM_FILE_TEMPLATE = CHROMIUM_SRC_URL + '/+/%s/%s'
 
-# Run these CQ trybots in addition to the default ones in infra/config/cq.cfg.
-EXTRA_TRYBOTS = 'tryserver.webrtc:win_baremetal,mac_baremetal,linux_baremetal'
-
 COMMIT_POSITION_RE = re.compile('^Cr-Commit-Position: .*#([0-9]+).*$')
 CLANG_REVISION_RE = re.compile(r'^CLANG_REVISION=(\d+)$')
 ROLL_BRANCH_NAME = 'roll_chromium_revision'
@@ -292,7 +289,6 @@ def GenerateCommitMessage(current_cr_rev, new_cr_rev, current_commit_pos,
     commit_msg.append('No update to Clang.\n')
 
   commit_msg.append('TBR=%s' % tbr_authors)
-  commit_msg.append('CQ_EXTRA_TRYBOTS=%s' % EXTRA_TRYBOTS)
   return '\n'.join(commit_msg)