Bug 1346333 - Ensure all TC mochitests get correct 'test-type' tag r=dustin

The previous attempt at this didn't handle jobs that were keyed by platform,
which was most of them.

MozReview-Commit-ID: IC602td532T

--HG--
extra : rebase_source : 95cdf9ad37df8ef6665665f11e59f8ae8304dbd2

taskcluster/taskgraph/transforms/tests.py

@@ -369,14 +369,6 @@ def set_treeherder_machine_platform(config, tests):
         yield test
 
 
-@transforms.add
-def set_mochitest_test_type(config, tests):
-    for test in tests:
-        if type(test['suite']) == str and test['suite'].startswith('mochitest'):
-            test.setdefault('tags', {})['test-type'] = 'mochitest'
-        yield test
-
-
 @transforms.add
 def set_asan_docker_image(config, tests):
     """Set the appropriate task.extra.treeherder.docker-image"""
@@ -607,6 +599,14 @@ def remove_linux_pgo_try_talos(config, tests):
         yield test
 
 
+@transforms.add
+def set_mochitest_test_type(config, tests):
+    for test in tests:
+        if 'mochitest' in test['suite']:
+            test.setdefault('tags', {})['test-type'] = 'mochitest'
+        yield test
+
+
 @transforms.add
 def make_job_description(config, tests):
     """Convert *test* descriptions to *job* descriptions (input to