Add fuchsia debug trybot

Bug: 758256
Change-Id: Icbd47e057881ec2dc2e2eb1cc733b5dd34326991
Reviewed-on: https://chromium-review.googlesource.com/1130499Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Ryan Tseng <hinoka@chromium.org>
Commit-Queue: Stephen Martinis <martiniss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574798}

infra/config/global/cr-buildbucket.cfg

@@ -2450,6 +2450,7 @@ buckets {
     }
     builders { mixins: "linux-try" name: "fuchsia_arm64" }
     builders { mixins: "linux-try" name: "fuchsia_arm64_cast_audio" }
+    builders { mixins: "linux-try" name: "fuchsia-fyi-x64-dbg" }
     builders { mixins: "linux-try" name: "fuchsia_x64" }
     builders { mixins: "linux-try" name: "fuchsia_x64_cast_audio" }
     builders { mixins: "linux-try" name: "leak_detection_linux" }

infra/config/global/luci-milo.cfg

@@ -4004,6 +4004,9 @@ consoles {
   builders {
     name: "buildbucket/luci.chromium.try/fuchsia_arm64_cast_audio"
   }
+  builders {
+    name: "buildbucket/luci.chromium.try/fuchsia-fyi-x64-dbg"
+  }
   builders {
     name: "buildbucket/luci.chromium.try/fuchsia_x64"
   }

tools/mb/mb_config.pyl

@@ -588,6 +588,7 @@
       'closure_compilation': 'closure_compilation',
       'fuchsia_arm64': 'release_trybot_fuchsia_arm64',
       'fuchsia_arm64_cast_audio': 'release_trybot_fuchsia_arm64_cast_audio',
+      'fucshia-fyi-x64-dbg': 'debug_trybot_fuchsia',
       'fuchsia_x64': 'release_trybot_fuchsia',
       'fuchsia_x64_cast_audio': 'release_trybot_fuchsia_cast_audio',
       'layout_test_leak_detection': 'release_trybot',
@@ -1248,6 +1249,10 @@
       'debug_trybot',
     ],
 
+    'debug_trybot_fuchsia': [
+      'debug_trybot', 'fuchsia',
+    ],
+
     'debug_trybot_x86': [
       'debug_trybot', 'x86',
     ],