Removed remaining obsolete button widget references (#67440)

dev/integration_tests/flutter_gallery/lib/demo/material/buttons_demo.dart

@@ -193,7 +193,7 @@ class _ButtonsDemoState extends State<ButtonsDemo> {
             children: <Widget>[
               TextButton.icon(
                 style: style,
-                icon: const Icon(Icons.add_circle_outlined, size: 18.0),
+                icon: const Icon(Icons.add_circle_outline, size: 18.0),
                 label: const Text('TEXT BUTTON', semanticsLabel: 'TEXT BUTTON 2'),
                 onPressed: () {
                   // Perform some action
@@ -201,7 +201,7 @@ class _ButtonsDemoState extends State<ButtonsDemo> {
               ),
               TextButton.icon(
                 style: style,
-                icon: const Icon(Icons.add_circle_outlined, size: 18.0),
+                icon: const Icon(Icons.add_circle_outline, size: 18.0),
                 label: const Text('DISABLED', semanticsLabel: 'DISABLED BUTTON 4'),
                 onPressed: null,
               ),

dev/integration_tests/ios_platform_view_tests/lib/main.dart

@@ -43,7 +43,7 @@ class _MyHomePageState extends State<MyHomePage> {
         title: Text(widget.title),
       ),
       body: Column(children: <Widget>[
-        FlatButton(
+        TextButton(
           key: const ValueKey<String>('platform_view_button'),
           child: const Text('show platform view'),
           onPressed: () {
@@ -55,7 +55,7 @@ class _MyHomePageState extends State<MyHomePage> {
           },
         ),
         // Push this button to perform an animation, which ensure the threads are unmerged after the animation.
-        RaisedButton(
+        ElevatedButton(
           key: const ValueKey<String>('unmerge_button'),
           child: const Text('Tap to unmerge threads'),
           onPressed: () {},
@@ -82,7 +82,7 @@ class PlatformViewPage extends StatelessWidget {
             width: 300,
             height: 300,
           ),
-          RaisedButton(
+          ElevatedButton(
             key: button,
             child: const Text('button'),
             onPressed: (){},

dev/integration_tests/ios_platform_view_tests/test_driver/main_test.dart

@@ -29,7 +29,7 @@ void main() {
       await driver.waitFor(plusButton);
       await driver.waitUntilNoTransientCallbacks();
 
-      // Tapping a raised button runs an animation that pumps enough frames to un-merge the threads.
+      // Tapping an elevated button runs an animation that pumps enough frames to un-merge the threads.
       await driver.tap(plusButton);
       await driver.waitUntilNoTransientCallbacks();
 
@@ -56,7 +56,7 @@ void main() {
       await driver.tap(backButton);
       await driver.waitUntilNoTransientCallbacks();
 
-      // The animation of tapping a `RaisedButton` should pump enough frames to un-merge the thread.
+      // The animation of tapping a `ElevatedButton` should pump enough frames to un-merge the thread.
       final SerializableFinder unmergeButton =
           find.byValueKey('unmerge_button');
       await driver.waitFor(unmergeButton);

examples/platform_view/lib/main.dart

@@ -72,7 +72,7 @@ class _MyHomePageState extends State<MyHomePage> {
                     ),
                     Padding(
                       padding: const EdgeInsets.all(18.0),
-                      child: RaisedButton(
+                      child: ElevatedButton(
                           child: Platform.isIOS
                               ? const Text('Continue in iOS view')
                               : const Text('Continue in Android view'),

packages/flutter/lib/src/material/pickers/date_range_picker_dialog.dart

@@ -10,7 +10,6 @@ import 'package:flutter/widgets.dart';
 
 import '../app_bar.dart';
 import '../back_button.dart';
-import '../button_theme.dart';
 import '../color_scheme.dart';
 import '../debug.dart';
 import '../dialog.dart';
@@ -518,12 +517,9 @@ class _CalendarRangePickerDialog extends StatelessWidget {
           ),
           actions: <Widget>[
             if (orientation == Orientation.landscape) entryModeIcon,
-            ButtonTheme(
-              minWidth: 64,
-              child: TextButton(
-                onPressed: onConfirm,
-                child: Text(confirmText, style: saveButtonStyle),
-              ),
+            TextButton(
+              onPressed: onConfirm,
+              child: Text(confirmText, style: saveButtonStyle),
             ),
             const SizedBox(width: 8),
           ],

packages/flutter/lib/src/widgets/navigator.dart

@@ -5550,7 +5550,7 @@ typedef RouteCompletionCallback<T> = void Function(T result);
 ///         mainAxisSize: MainAxisSize.min,
 ///         children: <Widget>[
 ///           Text('Last count: ${_lastCount.value}'),
-///           RaisedButton(
+///           ElevatedButton(
 ///             onPressed: () {
 ///               // Show the route defined by the `RestorableRouteFuture`.
 ///               _counterRoute.present('Awesome Counter');