Disable flaky test: BrowserAccessibilityWinTest.TestIAccessible2Relations.

BUG=929563
TBR=dmazzoni@chromium.org

Change-Id: I12c4ff8778cdfbdbf78c5bc09775bc3bd7541148
Reviewed-on: https://chromium-review.googlesource.com/c/1459316Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630045}

content/browser/accessibility/browser_accessibility_win_unittest.cc

@@ -2353,7 +2353,8 @@ TEST_F(BrowserAccessibilityWinTest, AccChildOnlyReturnsDescendants) {
                       child_unique_id_variant, result.GetAddressOf()));
 }
 
-TEST_F(BrowserAccessibilityWinTest, TestIAccessible2Relations) {
+// TODO(crbug.com/929563): Disabled due to flakiness.
+TEST_F(BrowserAccessibilityWinTest, DISABLED_TestIAccessible2Relations) {
   ui::AXNodeData root;
   root.id = 1;
   root.role = ax::mojom::Role::kRootWebArea;