Fix some issues with launching E2E benchmarks and add page delays in textfield benchmarks (#107500)

dev/benchmarks/macrobenchmarks/lib/src/text.dart

@@ -11,6 +11,7 @@ class TextPage extends StatelessWidget {
   Widget build(BuildContext context) {
     return Material(
       child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
         children: const <Widget>[
           SizedBox(
             width: 200,

dev/benchmarks/macrobenchmarks/test/textfield_perf_e2e.dart

@@ -12,11 +12,7 @@ void main() {
   macroPerfTestE2E(
     'textfield_perf',
     kTextRouteName,
-    // The driver version doesn't have this delay because the delay caused
-    // by the communication between the host and the test device is long enough
-    // for the driver test, but there isn't such delay in this host independent
-    // test.
-    pageDelay: const Duration(milliseconds: 50),
+    pageDelay: const Duration(seconds: 1),
     body: (WidgetController controller) async {
       final Finder textfield = find.byKey(const ValueKey<String>('basic-textfield'));
       controller.tap(textfield);

dev/benchmarks/macrobenchmarks/test/util.dart

@@ -25,9 +25,16 @@ void macroPerfTestE2E(
   ControlCallback? body,
   ControlCallback? setup,
 }) {
-  macroPerfTestMultiPageE2E(testName, <ScrollableButtonRoute>[
+  macroPerfTestMultiPageE2E(
+    testName,
+    <ScrollableButtonRoute>[
       ScrollableButtonRoute(kScrollableName, routeName),
-  ]);
+    ],
+    pageDelay: pageDelay,
+    duration: duration,
+    body: body,
+    setup: setup,
+  );
 }
 
 void macroPerfTestMultiPageE2E(

dev/benchmarks/macrobenchmarks/test_driver/textfield_perf_test.dart

@@ -11,6 +11,7 @@ void main() {
   macroPerfTest(
     'textfield_perf',
     kTextRouteName,
+    pageDelay: const Duration(seconds: 1),
     driverOps: (FlutterDriver driver) async {
       final SerializableFinder textfield = find.byValueKey('basic-textfield');
       driver.tap(textfield);