Added a more generous timeout period for the keyboard animation. (#62628)

dev/integration_tests/README.md

-Automated Flutter integration test suites. Each suite consists of either a
-complete Flutter app and a `flutter_driver` specification that drives tests
-from the UI, or a native app that is meant to integrate with Flutter for
-testing.
+# Automated Flutter integration test suites
+
+Each suite consists of either a complete Flutter app and a `flutter_driver`
+specification that drives tests from the UI, or a native app that is meant to
+integrate with Flutter for testing.
 
 Intended for use with devicelab tests.
 
-If you want to run a driver test locally, to debug a problem with a test,
-you can use this command from the appropriate subdirectory:
+If you want to run a driver test locally, to debug a problem with a test, you
+can use this command from the appropriate subdirectory:
 
 ```shell
-% flutter drive
+flutter drive -t <test> --driver <driver>
+```
+
+For example:
+
+```sh
+flutter drive -t lib/keyboard_resize.dart --driver test_driver/keyboard_resize_test.dart
 ```

dev/integration_tests/ui/test_driver/keyboard_resize_test.dart

@@ -33,22 +33,35 @@ void main() {
       final SerializableFinder defaultTextField = find.byValueKey(keys.kDefaultTextField);
       await driver.waitFor(defaultTextField);
       await driver.tap(defaultTextField);
-      await Future<void>.delayed(const Duration(seconds: 1));
 
+      bool heightTextDidShrink = false;
+      for (int i = 0; i < 3; ++i) {
+        await Future<void>.delayed(const Duration(seconds: 1));
         // Measure the height with keyboard displayed.
         final String heightWithKeyboardShown = await driver.getText(heightText);
-      expect(double.parse(heightWithKeyboardShown) < double.parse(startHeight), isTrue);
+        if (double.parse(heightWithKeyboardShown) < double.parse(startHeight)) {
+          heightTextDidShrink = true;
+          break;
+        }
+      }
+      expect(heightTextDidShrink, isTrue);
 
       // Unfocus the text field to dismiss the keyboard.
       final SerializableFinder unfocusButton = find.byValueKey(keys.kUnfocusButton);
       await driver.waitFor(unfocusButton);
       await driver.tap(unfocusButton);
-      await Future<void>.delayed(const Duration(seconds: 1));
 
+      bool heightTextDidExpand = false;
+      for (int i = 0; i < 3; ++i) {
+        await Future<void>.delayed(const Duration(seconds: 1));
         // Measure the final height.
         final String endHeight = await driver.getText(heightText);
-
-      expect(endHeight, startHeight);
+        if (endHeight == startHeight) {
+          heightTextDidExpand = true;
+          break;
+        }
+      }
+      expect(heightTextDidExpand, isTrue);
     });
   });
 }