[Driver] correct type for getWidgetDiagnostics (#45985)

packages/flutter_driver/lib/src/driver/driver.dart

@@ -619,7 +619,7 @@ class FlutterDriver {
   }) async {
     return _sendCommand(GetDiagnosticsTree(
       finder,
-      DiagnosticsType.renderObject,
+      DiagnosticsType.widget,
       subtreeDepth: subtreeDepth,
       includeProperties: includeProperties,
       timeout: timeout,

packages/flutter_driver/test/flutter_driver_test.dart

@@ -250,6 +250,42 @@ void main() {
       });
     });
 
+    group('getWidgetDiagnostics', () {
+      test('sends the getWidgetDiagnostics command', () async {
+        when(mockIsolate.invokeExtension(any, any)).thenAnswer((Invocation i) {
+          expect(i.positionalArguments[1], <String, dynamic>{
+            'command': 'get_diagnostics_tree',
+            'diagnosticsType': 'widget',
+            'finderType': 'ByTooltipMessage',
+            'text': 'foo',
+            'includeProperties': 'true',
+            'subtreeDepth': '0',
+            'timeout': _kSerializedTestTimeout,
+          });
+          return makeMockResponse(<String, dynamic>{});
+        });
+        await driver.getWidgetDiagnostics(find.byTooltip('foo'), timeout: _kTestTimeout);
+      });
+    });
+
+    group('getRenderObjectDiagnostics', () {
+      test('sends the getRenderObjectDiagnostics command', () async {
+        when(mockIsolate.invokeExtension(any, any)).thenAnswer((Invocation i) {
+          expect(i.positionalArguments[1], <String, dynamic>{
+            'command': 'get_diagnostics_tree',
+            'diagnosticsType': 'renderObject',
+            'finderType': 'ByTooltipMessage',
+            'text': 'foo',
+            'includeProperties': 'true',
+            'subtreeDepth': '0',
+            'timeout': _kSerializedTestTimeout,
+          });
+          return makeMockResponse(<String, dynamic>{});
+        });
+        await driver.getRenderObjectDiagnostics(find.byTooltip('foo'), timeout: _kTestTimeout);
+      });
+    });
+
     group('waitForCondition', () {
       test('sends the wait for NoPendingFrameCondition command', () async {
         when(mockIsolate.invokeExtension(any, any)).thenAnswer((Invocation i) {