Devicelab android emulator (#113472)

* Testing whether emulator is possible.

* Adding changes to see if emulator can be used from recipe.

* adding emulator support.

* Add the emulator flag for testing.

* Using string for boolean since it cannot be parsed in properties

* Checking to see if these changes are being used.

* Updated bool back to string

* Remove trailing whitespace from file.

.ci.yaml

@@ -1385,6 +1385,7 @@ targets:
       tags: >
         ["devicelab" ,"android", "linux"]
       task_name: android_defines_test
+      use_emulator: "true"
 
   - name: Linux_android android_obfuscate_test
     recipe: devicelab/devicelab_drone

dev/devicelab/bin/run.dart

@@ -62,6 +62,9 @@ Future<void> main(List<String> rawArgs) async {
   /// Path to write test results to.
   final String? resultsPath = args['results-file'] as String?;
 
+  /// Use an emulator for this test if it is an android test.
+  final bool useEmulator = (args['use-emulator'] as bool?) ?? false;
+
   if (args.wasParsed('list')) {
     for (int i = 0; i < taskNames.length; i++) {
       print('${(i + 1).toString().padLeft(3)} - ${taskNames[i]}');
@@ -107,6 +110,7 @@ Future<void> main(List<String> rawArgs) async {
       gitBranch: gitBranch,
       luciBuilder: luciBuilder,
       resultsPath: resultsPath,
+      useEmulator: useEmulator,
     );
   }
 }
@@ -319,6 +323,11 @@ ArgParser createArgParser(List<String> taskNames) {
             'running when a task is completed. If any Dart processes are terminated '
             'in this way, the test is considered to have failed.',
     )
+    ..addFlag(
+      'use-emulator',
+      help: 'If this is an android test, use an emulator to run the test instead of '
+            'a physical device.'
+    )
     ..addMultiOption(
       'test',
       hide: true,

dev/devicelab/lib/command/test.dart

@@ -51,6 +51,10 @@ class TestCommand extends Command<void> {
       'silent',
       help: 'Suppresses standard output and only print standard error output.',
     );
+    argParser.addFlag(
+      'use-emulator',
+      help: 'Use an emulator instead of a device to run tests.'
+    );
   }
 
   @override
@@ -74,6 +78,7 @@ class TestCommand extends Command<void> {
       luciBuilder: argResults!['luci-builder'] as String?,
       resultsPath: argResults!['results-file'] as String?,
       silent: (argResults!['silent'] as bool?) ?? false,
+      useEmulator: (argResults!['use-emulator'] as bool?) ?? false,
       taskArgs: taskArgs,
     );
   }

dev/devicelab/lib/framework/runner.dart

@@ -39,6 +39,7 @@ Future<void> runTasks(
   String? luciBuilder,
   String? resultsPath,
   List<String>? taskArgs,
+  bool useEmulator = false,
   @visibleForTesting Map<String, String>? isolateParams,
   @visibleForTesting Function(String) print = print,
   @visibleForTesting List<String>? logs,
@@ -59,6 +60,7 @@ Future<void> runTasks(
         gitBranch: gitBranch,
         luciBuilder: luciBuilder,
         isolateParams: isolateParams,
+        useEmulator: useEmulator,
       );
 
       if (!result.succeeded) {
@@ -104,6 +106,7 @@ Future<TaskResult> rerunTask(
   String? resultsPath,
   String? gitBranch,
   String? luciBuilder,
+  bool useEmulator = false,
   @visibleForTesting Map<String, String>? isolateParams,
 }) async {
   section('Running task "$taskName"');
@@ -116,6 +119,7 @@ Future<TaskResult> rerunTask(
     silent: silent,
     taskArgs: taskArgs,
     isolateParams: isolateParams,
+    useEmulator: useEmulator,
   );
 
   print('Task result:');
@@ -152,6 +156,7 @@ Future<TaskResult> runTask(
   String? localEngineSrcPath,
   String? deviceId,
   List<String>? taskArgs,
+  bool useEmulator = false,
   @visibleForTesting Map<String, String>? isolateParams,
 }) async {
   final String taskExecutable = 'bin/tasks/$taskName.dart';
@@ -160,6 +165,13 @@ Future<TaskResult> runTask(
     throw 'Executable Dart file not found: $taskExecutable';
   }
 
+  if (useEmulator) {
+    taskArgs ??= <String>[];
+    taskArgs
+      ..add('--android-emulator')
+      ..add('--browser-name=android-chrome');
+  }
+
   final Process runner = await startProcess(
     dartBin,
     <String>[

dev/devicelab/lib/framework/utils.dart

@@ -283,6 +283,7 @@ Future<Process> startProcess(
   newEnvironment['BOT'] = isBot ? 'true' : 'false';
   newEnvironment['LANG'] = 'en_US.UTF-8';
   print('Executing "$command" in "$finalWorkingDirectory" with environment $newEnvironment');
+
   final Process process = await _processManager.start(
     <String>[executable, ...?arguments],
     environment: newEnvironment,