Enable WebViewAccessiblityTest for OOPIF webview.

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index d98c2de00541437bd0ac054aff8c88b340403e46..5602266464ff9bae4e0522d07ae4be4909b68341 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -486,6 +486,7 @@ class CONTENT_EXPORT WebContentsImpl
   std::unique_ptr<WebUIImpl> CreateWebUIForRenderFrameHost(
       const GURL& url) override;
   void SetFocusedFrame(FrameTreeNode* node, SiteInstance* source) override;
+  RenderFrameHost* GetFrameAtNode(FrameTreeNode* tree_node) override;
   void OnFocusedElementChangedInFrame(
       RenderFrameHostImpl* frame,
       const gfx::Rect& bounds_in_root_view) override;
@@ -848,9 +849,10 @@ class CONTENT_EXPORT WebContentsImpl
     WebContentsTreeNode();
     ~WebContentsTreeNode();
 
-    typedef std::set<WebContentsTreeNode*> ChildrenSet;
+    typedef std::map<int, WebContentsImpl*> ChildrenMap;
 
-    void ConnectToOuterWebContents(WebContentsImpl* outer_web_contents,
+    void ConnectToOuterWebContents(WebContentsImpl* web_contents,
+                                   WebContentsImpl* outer_web_contents,
                                    RenderFrameHostImpl* outer_contents_frame);
 
     WebContentsImpl* outer_web_contents() { return outer_web_contents_; }
@@ -861,13 +863,17 @@ class CONTENT_EXPORT WebContentsImpl
     WebContentsImpl* focused_web_contents() { return focused_web_contents_; }
     void SetFocusedWebContents(WebContentsImpl* web_contents);
 
+    // Returns the WebContents at a tree node in the frame tree or nullptr if
+    // there is none.
+    WebContentsImpl* find_contents_at_node(int frame_tree_node_id);
+
    private:
     // The outer WebContents.
     WebContentsImpl* outer_web_contents_;
     // The ID of the FrameTreeNode in outer WebContents that is hosting us.
     int outer_contents_frame_tree_node_id_;
     // List of inner WebContents that we host.
-    ChildrenSet inner_web_contents_tree_nodes_;
+    ChildrenMap inner_web_contents_tree_nodes_;
     // Only the root node should have this set. This indicates the WebContents
     // whose frame tree has the focused frame. The WebContents tree could be
     // arbitrarily deep.