Bug 1596280 - Make consistently passing linux64-ccov-opt suites tier 2. r=jmaher

Differential Revision: https://phabricator.services.mozilla.com/D53183

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

taskcluster/ci/test/compiled.yml

@@ -65,6 +65,7 @@ gtest:
             windows10-64-pgo.*: 3
             windows10-64-asan.*: 3
             windows10-aarch64.*: 2
+            linux64-ccov/opt: 3
             default: default
 
 jittest:

taskcluster/ci/test/mochitest.yml

@@ -49,6 +49,7 @@ mochitest:
     tier:
         by-test-platform:
             windows10-aarch64.*: 2
+            linux64-ccov/opt: 3
             default: default
     chunks:
         by-test-platform:
@@ -96,6 +97,7 @@ mochitest-browser-chrome:
     tier:
         by-test-platform:
             windows10-aarch64.*: 2
+            linux64-ccov/opt: 3
             default: default
     chunks:
         by-test-platform:
@@ -174,6 +176,7 @@ mochitest-devtools-chrome:
     tier:
         by-test-platform:
             windows10-aarch64.*: 2
+            linux64-ccov/opt: 3
             default: default
     max-run-time:
         by-test-platform:

taskcluster/ci/test/web-platform.yml

@@ -66,6 +66,7 @@ web-platform-tests:
             linux64-asan/opt: 2
             windows10-aarch64.*: 2
             .*-qr/.*: 2  # can't be tier-1 if it's not running on integration branches
+            linux64-ccov/opt: 3
             default: default
     mozharness:
         chunked: true
@@ -128,6 +129,7 @@ web-platform-tests-wdspec:
             android.*: 3
             linux64-asan/opt: 2
             .*-qr/.*: 2  # can't be tier-1 if it's not running on integration branches
+            linux64-ccov/opt: 3
             default: default
 
 web-platform-tests-wdspec-headless:

taskcluster/ci/test/xpcshell.yml

@@ -68,6 +68,7 @@ xpcshell:
         by-test-platform:
             windows10-64-asan.*: 3
             windows10-aarch64.*: 2
+            linux64-ccov/opt: 3
             default: default
     fetches:
         toolchain:

taskcluster/taskgraph/transforms/tests.py

@@ -1078,10 +1078,6 @@ def enable_code_coverage(config, tests):
                 test['run-on-projects'] = []
                 continue
 
-            # For now, make all ccov opt tests tier-3.
-            if 'opt' in test['build-platform']:
-                test['tier'] = 3
-
             # Skip this transform for android code coverage builds.
             if 'android' in test['build-platform']:
                 test.setdefault('fetches', {}).setdefault('toolchain', []).append('linux64-grcov')