Remove references to tryserver.chromium.gpu

[email protected]
BUG=426897

Review URL: https://codereview.chromium.org/960773002

Cr-Commit-Position: refs/heads/master@{#318203}
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index a84f3f9..a57a2c0 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -1698,9 +1698,7 @@
   }
   master = master_map.get(bot)
   if not master:
-    if 'gpu' in bot:
-      master = 'tryserver.chromium.gpu'
-    elif 'linux' in bot or 'android' in bot or 'presubmit' in bot:
+    if 'linux' in bot or 'android' in bot or 'presubmit' in bot:
       master = 'tryserver.chromium.linux'
     elif 'win' in bot:
       master = 'tryserver.chromium.win'