Bug 1877861 - run cppunittest against android x86 builds r=jcristau,taskgraph-reviewers,jmaher

Currently there are no tests run against geckoview x86 builds. One consequence
of this is that geckoview x86 artifact builds are not available. Since there
are no x86 artifact builds, build-fat-aar must wait for the non-artifact x86
build to complete after the x86_64, arm7, and aarch64 artifact builds complete.
The planned fenix and other firefox-android builds coming to mozilla-central
soon will rely on build-fat-aar, so we want these builds to be efficient.
This patch adds a minimal test set for geckoview x86 to enable x86 artifact
builds. cppunit tests are selected because they are one of the few test suites
which run trouble-free on x86, they are conceivably abi-sensitive, and they
add minimal test load (they complete quickly).

Differential Revision: https://phabricator.services.mozilla.com/D200406

taskcluster/ci/build/android.yml

@@ -98,6 +98,7 @@ android-x86/opt:
     worker:
         env:
             TOOLTOOL_MANIFEST: "mobile/android/config/tooltool-manifests/android-x86/releng.manifest"
+            MOZ_AUTOMATION_PACKAGE_TESTS: "1"
     run:
         actions: [get-secrets, build]
         config: ["builds/releng_base_android_64_builds.py"]

taskcluster/ci/test/test-platforms.yml

@@ -438,6 +438,11 @@ android-em-7.0-x86_64-qr/debug-isolated-process:
     test-sets:
         - android-x86_64-tests
 
+android-em-7.0-x86-qr/opt:
+    build-platform: android-x86/opt
+    test-sets:
+        - android-x86-tests
+
 # android-hw test platforms execute on real devices attached to Autophone hosts.
 
 # android-hw-a51-11-0 Samsung Galaxy A51 Android 11.0

taskcluster/ci/test/test-sets.yml

@@ -454,6 +454,9 @@ android-x86_64-tests:
     - web-platform-tests-wdspec
     - xpcshell
 
+android-x86-tests:
+    - cppunittest
+
 android-hw-aarch64-opt-unittests:
     - jittest
 

taskcluster/gecko_taskgraph/transforms/test/other.py

@@ -169,6 +169,10 @@ def set_treeherder_machine_platform(config, tasks):
             task["treeherder-machine-platform"] = task["test-platform"].replace(
                 ".", "-"
             )
+        elif "android-em-7.0-x86-qr" in task["test-platform"]:
+            task["treeherder-machine-platform"] = task["test-platform"].replace(
+                ".", "-"
+            )
         elif "-qr" in task["test-platform"]:
             task["treeherder-machine-platform"] = task["test-platform"]
         elif "android-hw" in task["test-platform"]:
@@ -755,7 +759,7 @@ test_setting_description_schema = Schema(
     {
         Required("_hash"): str,
         "platform": {
-            Required("arch"): Any("32", "64", "aarch64", "arm7", "x86_64"),
+            Required("arch"): Any("32", "64", "aarch64", "arm7", "x86", "x86_64"),
             Required("os"): {
                 Required("name"): Any("android", "linux", "macosx", "windows"),
                 Required("version"): str,