Fix some errors in snippets (flutter#87528)

Author: gspencergoog

.cirrus.yml

@@ -67,16 +67,15 @@ task:
       - date
       - which flutter
   matrix:
-    # TODO(flutter): https://github.com/flutter/flutter/issues/87517 analyze linux is only failing on Cirrus due to an unknown snippets issue
-    # - name: analyze-linux # linux-only
-    #   only_if: "$CIRRUS_PR != ''"
-    #   environment:
-    #     # Empirically, the analyze-linux shard runs surprisingly fast (under 15 minutes) with just 1
-    #     # CPU.  We noticed OOM failures with 6GB 4/2020, so we increased the memory.
-    #     CPU: 1
-    #     MEMORY: 8G
-    #   script:
-    #     - dart --enable-asserts ./dev/bots/analyze.dart
+    - name: analyze-linux # linux-only
+      only_if: "$CIRRUS_PR != ''"
+      environment:
+        # Empirically, the analyze-linux shard runs surprisingly fast (under 15 minutes) with just 1
+        # CPU.  We noticed OOM failures with 6GB 4/2020, so we increased the memory.
+        CPU: 1
+        MEMORY: 8G
+      script:
+        - dart --enable-asserts ./dev/bots/analyze.dart
 
     - name: framework_tests-widgets-linux
       only_if: "changesInclude('.cirrus.yml', 'dev/**', 'packages/flutter/**', 'packages/flutter_test/**', 'packages/flutter_tools/lib/src/test/**', 'bin/**') && $CIRRUS_PR != ''"

dev/bots/analyze.dart

@@ -106,7 +106,7 @@ Future<void> run(List<String> arguments) async {
   // Analyze all the sample code in the repo
   print('$clock Sample code...');
   await runCommand(dart,
-    <String>[path.join(flutterRoot, 'dev', 'bots', 'analyze_sample_code.dart')],
+    <String>[path.join(flutterRoot, 'dev', 'bots', 'analyze_sample_code.dart'), '--verbose'],
     workingDirectory: flutterRoot,
   );
 

packages/flutter/lib/src/cupertino/context_menu.dart

@@ -212,7 +212,7 @@ class CupertinoContextMenu extends StatefulWidget {
   ///       onPressed: () {},
   ///     ),
   ///   ],
-  /// ),
+  /// )
   /// ```
   ///
   /// {@end-tool}

packages/flutter/lib/src/material/list_tile.dart

@@ -429,7 +429,7 @@ enum ListTileControlAffinity {
 ///   ),
 ///   title: const Text('title'),
 ///   dense: false,
-/// ),
+/// )
 /// ```
 /// {@end-tool}
 ///

packages/flutter/lib/src/material/progress_indicator_theme.dart

@@ -138,16 +138,15 @@ class ProgressIndicatorThemeData with Diagnosticable {
 /// {@tool snippet}
 ///
 /// Here is an example of a progress indicator theme that applies a red indicator
-/// color with a slightly transparent red for the background track color.
+/// color.
 ///
 /// ```dart
-/// ProgressIndicatorTheme(
+/// const ProgressIndicatorTheme(
 ///   data: ProgressIndicatorThemeData(
 ///     color: Colors.red,
-///     backgroundColor: Colors.red.withOpacity(0.25),
 ///   ),
 ///   child: LinearProgressIndicator()
-/// ),
+/// )
 /// ```
 /// {@end-tool}
 class ProgressIndicatorTheme extends InheritedTheme {

packages/flutter/lib/src/material/text_selection_theme.dart

@@ -128,7 +128,7 @@ class TextSelectionThemeData with Diagnosticable {
 ///     selectionHandleColor: Colors.lightBlue,
 ///   ),
 ///   child: TextField(),
-/// ),
+/// )
 /// ```
 /// {@end-tool}
 class TextSelectionTheme extends InheritedTheme {

packages/flutter/lib/src/material/tooltip_theme.dart

@@ -239,7 +239,7 @@ class TooltipThemeData with Diagnosticable {
 ///       onPressed: () {},
 ///     ),
 ///   ),
-/// ),
+/// )
 /// ```
 /// {@end-tool}
 class TooltipTheme extends InheritedTheme {

packages/flutter/lib/src/painting/strut_style.dart

@@ -282,7 +282,7 @@ import 'text_style.dart';
 ///     fontSize: 14,
 ///     forceStrutHeight: true,
 ///   ),
-/// ),
+/// )
 /// ```
 /// {@end-tool}
 ///