Bug 1517298 - TB Mochhitest configuration for taskcluster. r=darktrojan

Adds the necessary taskcluster and mozharness configuration for Thunderbird
Mochitests.
Note that the addition of "all_mochitest_suites" in thunderbird_extra.py will
replace the inherited list of mochitests from "*_taskcluster_unittest.py".

Differential Revision: https://phabricator.services.mozilla.com/D16376

--HG--
extra : moz-landing-system : lando

mozharness/unittests/thunderbird_extra.py

@@ -18,4 +18,8 @@ config = {
     "all_mozmill_suites": {
         "mozmill": ["--list=tests/mozmill/mozmilltests.list"],
     },
+    "all_mochitest_suites": {
+        "browser-chrome-thunderbird": ["--flavor=browser",
+                                       "--subsuite=thunderbird"],
+    },
 }

taskcluster/ci/config.yml

@@ -18,6 +18,10 @@ treeherder:
         'Fetch-URL': 'Fetch and store content'
         'L10n': 'Localised Repacks'
         'L10n-Rpk': 'Localized Repackaged Repacks'
+        'M': 'Mochitests'
+        'M-sw': 'Mochitests with serviceworker redesign'
+        'M-e10s': 'Mochitests with e10s'
+        'M-sw-e10s': 'Mochitests with serviceworker redesign and e10s'
         'ms': 'Complete MAR signing'
         'MSI': 'Repack installers into MSIs'
         'MSIs': 'Signing of Repacked installers of MSIs'

taskcluster/ci/test/kind.yml

@@ -7,6 +7,8 @@ loader: taskgraph.loader.test:loader
 kind-dependencies:
     - build
     - build-signing
+    - fetch
+    - toolchain
 
 transforms:
     - taskgraph.transforms.tests:transforms

taskcluster/ci/test/test-sets.yml

@@ -18,3 +18,4 @@
 common-tests:
     - xpcshell
     - mozmill
+    - mochitest-thunderbird

taskcluster/ci/test/tests.yml

@@ -105,3 +105,30 @@ mozmill:
         extra-options:
             - "--mozmill-suite=mozmill"
         requires-signed-builds: false
+
+mochitest-thunderbird:
+    description: "Mochitest browser-chrome-thunderbird run"
+    suite: mochitest/browser-chrome-thunderbird
+    treeherder-symbol: M(bct)
+    run-on-projects: []  # Don't run during testing phase
+    loopback-video: true
+    max-run-time: 3600
+    e10s: true
+    serviceworker-e10s: false
+    mozharness:
+        script: desktop_unittest.py
+        mochitest-flavor: browser
+        config:
+            by-test-platform:
+                windows.*:
+                    - unittests/win_taskcluster_unittest.py
+                    - unittests/thunderbird_extra.py
+                macosx64.*:
+                    - unittests/mac_unittest.py
+                    - unittests/thunderbird_extra.py
+                linux.*:
+                    - unittests/linux_unittest.py
+                    - remove_executables.py
+                    - unittests/thunderbird_extra.py
+    instance-size: default
+    allow-software-gl-layers: false