Remove WebKit Win/Mac Builder from Milo config.

Bug: 907562
Change-Id: Iffe499a9329501cf0a1e439be29f606c746737a6
Reviewed-on: https://chromium-review.googlesource.com/c/1351096Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Jao-ke Chin-Lee <jchinlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610984}

infra/config/global/luci-milo.cfg

@@ -720,21 +720,11 @@ consoles {
     category: "chromium.memory|android"
     short_name: "cfi"
   }
-  builders {
-    name: "buildbot/chromium.webkit/WebKit Win Builder"
-    category: "chromium.webkit|win|bld"
-    short_name: "32"
-  }
   builders {
     name: "buildbucket/luci.chromium.ci/WebKit Win10"
     category: "chromium.webkit|win|tst"
     short_name: "10"
   }
-  builders {
-    name: "buildbot/chromium.webkit/WebKit Mac Builder"
-    category: "chromium.webkit|mac"
-    short_name: "bld"
-  }
   builders {
     name: "buildbucket/luci.chromium.ci/WebKit Mac10.13 (retina)"
     category: "chromium.webkit|mac"
@@ -1171,21 +1161,11 @@ consoles {
   repo_url: "https://chromium.googlesource.com/chromium/src"
   refs: "refs/heads/master"
   manifest_name: "REVISION"
-  builders {
-    name: "buildbot/chromium.webkit/WebKit Win Builder"
-    category: "win|bld"
-    short_name: "32"
-  }
   builders {
     name: "buildbucket/luci.chromium.ci/WebKit Win10"
     category: "win|tst"
     short_name: "10"
   }
-  builders {
-    name: "buildbot/chromium.webkit/WebKit Mac Builder"
-    category: "mac"
-    short_name: "bld"
-  }
   builders {
     name: "buildbucket/luci.chromium.ci/WebKit Mac10.13 (retina)"
     category: "mac"