Add the current gardener to the common chromium header on Milo.

This will display the current gardener on build.chromium.org pages
under the "Oncalls" box next to chromium, android, ios, etc sheriffs.

Gardeners are responsible for ensuring frequent uprevs of Chrome into
Chrome OS. A big part of that is monitoring & resolving Chrome
build/test regressions on Chrome OS. Hence why adding them to the list
of browser oncalls makes sense.

Ideally this will also provide a good point of contact for general
CrOS-related tests and build bugs/questions that non-CrOS chromium
devs may have.

Bug: None
Change-Id: I9367acc2871661d2ec69ec9ce2a29d7c758a06d8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2416944Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: Erik Staab <estaab@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814752}

infra/config/chromium-header.textpb

@@ -10,6 +10,10 @@ oncalls {
   name: "iOS"
   url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
 }
+oncalls {
+  name: "ChromeOS"
+  url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+}
 oncalls {
   name: "GPU"
   url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"

infra/config/generated/luci-milo.cfg

@@ -508,6 +508,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -1198,6 +1202,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -1503,6 +1511,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -1949,6 +1961,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -2289,6 +2305,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -2773,6 +2793,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -3073,6 +3097,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -3408,6 +3436,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -3887,6 +3919,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -4282,6 +4318,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -4706,6 +4746,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -5362,6 +5406,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -5729,6 +5777,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -6113,6 +6165,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -6444,6 +6500,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -7129,6 +7189,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -7499,6 +7563,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -7839,6 +7907,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -8204,6 +8276,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -8498,6 +8574,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -8843,6 +8923,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -9163,6 +9247,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -9523,6 +9611,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -9853,6 +9945,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -10258,6 +10354,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"
@@ -10584,6 +10684,10 @@ consoles {
       name: "iOS"
       url: "https://rota-ng.appspot.com/legacy/sheriff_ios.json"
     }
+    oncalls {
+      name: "ChromeOS"
+      url: "https://chrome-ops-rotation-proxy.appspot.com/current/oncallator:chromeos-gardeners"
+    }
     oncalls {
       name: "GPU"
       url: "https://rota-ng.appspot.com/legacy/sheriff_gpu.json"