Add a test for <dialog> in the accessibility tree

content/browser/accessibility/dump_accessibility_tree_browsertest.cc

Index: content/browser/accessibility/dump_accessibility_tree_browsertest.cc
diff --git a/content/browser/accessibility/dump_accessibility_tree_browsertest.cc b/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
index 948b8fde628a31e854ae66bdf64faaba94c54c9b..cfad08ddeed288f824eb6319a2833ea236c93232 100644
--- a/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
+++ b/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
@@ -332,6 +332,10 @@ IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
   RunTest(FILE_PATH_LITERAL("checkbox-name-calc.html"));
 }
 
+IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest, AccessibilityDialog) {
+  RunTest(FILE_PATH_LITERAL("dialog.html"));
+}
+
 IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest, AccessibilityDiv) {
   RunTest(FILE_PATH_LITERAL("div.html"));
 }