Make DevToolsTable.rowItemExtent non-nullable (#8868)

packages/devtools_app/lib/src/app.dart

diff --git a/packages/devtools_app/lib/src/app.dart b/packages/devtools_app/lib/src/app.dart
index c09266d..2147c84 100644
--- a/packages/devtools_app/lib/src/app.dart
+++ b/packages/devtools_app/lib/src/app.dart
@@ -523,7 +523,7 @@
   /// widgets depending on this controller can access it by calling
   /// `Provider<C>.of(context)`.
   ///
-  /// If [createController] and [controller] are both null, [screen] will be
+  /// If [createController] and `controller` are both null, [screen] will be
   /// responsible for creating and maintaining its own controller.
   ///
   /// In the controller initialization, if logic requires a connected [VmService]

packages/devtools_app/lib/src/shared/table/table.dart

diff --git a/packages/devtools_app/lib/src/shared/table/table.dart b/packages/devtools_app/lib/src/shared/table/table.dart
index 68dfe44..0a7bd9d 100644
--- a/packages/devtools_app/lib/src/shared/table/table.dart
+++ b/packages/devtools_app/lib/src/shared/table/table.dart
@@ -83,7 +83,7 @@
     this.startScrolledAtBottom = false,
     this.preserveVerticalScrollPosition = false,
     this.activeSearchMatchNotifier,
-    this.rowItemExtent,
+    required this.rowItemExtent,
     this.tallHeaders = false,
     this.headerColor,
     this.fillWithEmptyRows = false,
@@ -95,7 +95,7 @@
   final bool startScrolledAtBottom;
   final List<double> columnWidths;
   final IndexedScrollableWidgetBuilder rowBuilder;
-  final double? rowItemExtent;
+  final double rowItemExtent;
   final FocusNode? focusNode;
   final TableKeyEventHandler? handleKeyEvent;
   final ValueNotifier<Selection<T?>>? selectionNotifier;
@@ -347,7 +347,7 @@
   }
 
   double _pinnedDataHeight(BoxConstraints tableConstraints) => min(
-    widget.rowItemExtent! * pinnedData.length,
+    widget.rowItemExtent * pinnedData.length,
     tableConstraints.maxHeight / 2,
   );
 
@@ -371,7 +371,7 @@
           _pinnedDataHeight(tableConstraints) + ThickDivider.thickDividerHeight;
     }
 
-    return max(_data.length, maxHeight ~/ widget.rowItemExtent!);
+    return max(_data.length, maxHeight ~/ widget.rowItemExtent);
   }
 
   Widget _buildItem(BuildContext context, int index, {bool isPinned = false}) {