Add aria-owns DumpAccessibilityTree test and make it pass.

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 288e6e466e6c7fde8b21fa33087126223c5c6ed6..46765b95012d6ccfa41de55c508abbd6e7a2a597 100644
--- a/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
+++ b/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
@@ -401,6 +401,10 @@ IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
   RunAriaTest(FILE_PATH_LITERAL("aria-orientation.html"));
 }
 
+IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest, AccessibilityAriaOwns) {
+  RunAriaTest(FILE_PATH_LITERAL("aria-owns.html"));
+}
+
 IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest, AccessibilityAriaMath) {
   RunAriaTest(FILE_PATH_LITERAL("aria-math.html"));
 }