Clean up startProgress logic. (#19695) (#20009)

Disallow calling stop() or cancel() multiple times. This means that
when you use startProgress you have to more carefully think about what
exactly is going on.

Properly cancel startProgress in non-ANSI situations, so that
back-to-back startProgress calls all render to the console.

dev/devicelab/README.md

@@ -106,6 +106,18 @@ You must set the `ANDROID_HOME` environment variable to run tests on Android. If
 you have a local build of the Flutter engine, then you have a copy of the
 Android SDK at `.../engine/src/third_party/android_tools/sdk`.
 
+You can find where your Android SDK is using `flutter doctor`.
+
+## Running all tests
+
+To run all tests defined in `manifest.yaml`, use option `-a` (`--all`):
+
+```sh
+dart bin/run.dart -a
+```
+
+## Running specific tests
+
 To run a test, use option `-t` (`--task`):
 
 ```sh
@@ -127,20 +139,15 @@ To run multiple tests, repeat option `-t` (`--task`) multiple times:
 dart bin/run.dart -t test1 -t test2 -t test3
 ```
 
-To run all tests defined in `manifest.yaml`, use option `-a` (`--all`):
+To run tests from a specific stage, use option `-s` (`--stage`).
+Currently there are only three stages defined, `devicelab`,
+`devicelab_ios` and `devicelab_win`.
 
-```sh
-dart bin/run.dart -a
-```
-
-To run tests from a specific stage, use option `-s` (`--stage`):
 
 ```sh
 dart bin/run.dart -s {NAME_OF_STAGE}
 ```
 
-Currently there are only three stages defined, `devicelab`, `devicelab_ios` and `devicelab_win`.
-
 # Reproducing broken builds locally
 
 To reproduce the breakage locally `git checkout` the corresponding Flutter

dev/devicelab/bin/tasks/flutter_attach_test.dart

@@ -31,14 +31,13 @@ Future<void> testReload(Process process, { Future<void> Function() onListening }
       .listen((String line) {
     print('attach:stdout: $line');
     stdout.add(line);
-    if (line.contains('Waiting') && onListening != null) {
+    if (line.contains('Waiting') && onListening != null)
       listening.complete(onListening());
-    }
     if (line.contains('To quit, press "q".'))
       ready.complete();
     if (line.contains('Reloaded '))
       reloaded.complete();
-    if (line.contains('Restarted app in '))
+    if (line.contains('Restarted application in '))
       restarted.complete();
     if (line.contains('Application finished'))
       finished.complete();
@@ -91,7 +90,7 @@ void main() {
     await device.unlock();
     final Directory appDir = dir(path.join(flutterDirectory.path, 'dev/integration_tests/ui'));
     await inDirectory(appDir, () async {
-      section('Build: starting...');
+      section('Building');
       final String buildStdout = await eval(
           path.join(flutterDirectory.path, 'bin', 'flutter'),
           <String>['--suppress-analytics', 'build', 'apk', '--debug', 'lib/main.dart'],
@@ -105,7 +104,7 @@ void main() {
       await device.adb(<String>['install', '-r', apkPath]);
 
       try {
-        section('Launching attach.');
+        section('Launching `flutter attach`');
         Process attachProcess = await startProcess(
           path.join(flutterDirectory.path, 'bin', 'flutter'),
           <String>['--suppress-analytics', 'attach', '-d', device.deviceId],
@@ -113,7 +112,6 @@ void main() {
         );
 
         await testReload(attachProcess, onListening: () async {
-          section('Launching app.');
           await device.shellExec('am', <String>['start', '-n', kActivityId]);
         });
 
@@ -124,15 +122,16 @@ void main() {
 
         final String currentTime = (await device.shellEval('date', <String>['"+%F %R:%S.000"'])).trim();
         print('Start time on device: $currentTime');
-        section('Launching app');
+        section('Relaunching application');
         await device.shellExec('am', <String>['start', '-n', kActivityId]);
 
+        // If the next line fails, your device may not support regexp search.
         final String observatoryLine = await device.adb(<String>['logcat', '-e', 'Observatory listening on http:', '-m', '1', '-T', currentTime]);
         print('Found observatory line: $observatoryLine');
         final String observatoryPort = new RegExp(r'Observatory listening on http://.*:([0-9]+)').firstMatch(observatoryLine)[1];
         print('Extracted observatory port: $observatoryPort');
 
-        section('Launching attach with given port.');
+        section('Launching attach with given port');
         attachProcess = await startProcess(
           path.join(flutterDirectory.path, 'bin', 'flutter'),
           <String>['--suppress-analytics', 'attach', '--debug-port', observatoryPort, '-d', device.deviceId],

dev/devicelab/bin/tasks/run_release_test.dart

@@ -58,6 +58,8 @@ void main() {
         stdout.removeAt(0);
       if (stdout.first == 'Initializing gradle...')
         stdout.removeAt(0);
+      if (stdout.first == 'Resolving dependencies...')
+        stdout.removeAt(0);
       if (!(stdout.first.startsWith('Launching lib/main.dart on ') && stdout.first.endsWith(' in release mode...')))
         throw 'flutter run --release had unexpected first line: ${stdout.first}';
       stdout.removeAt(0);