Enable WebViewAccessiblityTest for OOPIF webview.

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index dc37d70fa1a319fa318cd42415df1a3586266418..b9cd74ece30a5562d9feaec7d9f5435e4dcf6f20 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -3329,14 +3329,10 @@ void RenderFrameHostImpl::AXContentTreeDataToAXTreeData(
     return;
 
   // For the root frame tree node, also store the AXTreeID of the focused frame.
-  // TODO(avallee): https://crbug.com/610795: No focus ax events.
-  // This is probably where we need to fix the bug to enable the test.
-  FrameTreeNode* focused_frame_tree_node = frame_tree_->GetFocusedFrame();
-  if (!focused_frame_tree_node)
+  auto* focused_frame = static_cast<RenderFrameHostImpl*>(
+      delegate_->GetFocusedFrameIncludingInnerWebContents());
+  if (!focused_frame)
     return;
-  RenderFrameHostImpl* focused_frame =
-      focused_frame_tree_node->current_frame_host();
-  DCHECK(focused_frame);
   dst->focused_tree_id = focused_frame->GetAXTreeID();
 }