Re-enable FocusBeforeNavigation test.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 232504b30c18a519fdeaf99001d086fc1f39f8e9..fdce9648ed1acba35818b3218122321255de78ec 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -1451,11 +1451,14 @@ void WebContentsImpl::AttachToOuterWebContentsFrame(
   if (!render_manager->GetRenderWidgetHostView())
     CreateRenderWidgetHostViewForRenderManager(GetRenderViewHost());
 
+  auto* outer_web_contents_impl =
+      static_cast<WebContentsImpl*>(outer_web_contents);
+  auto* outer_contents_frame_impl =
+      static_cast<RenderFrameHostImpl*>(outer_contents_frame);
   // Create a link to our outer WebContents.
   node_.reset(new WebContentsTreeNode());
-  node_->ConnectToOuterWebContents(
-      this, static_cast<WebContentsImpl*>(outer_web_contents),
-      static_cast<RenderFrameHostImpl*>(outer_contents_frame));
+  node_->ConnectToOuterWebContents(this, outer_web_contents_impl,
+                                   outer_contents_frame_impl);
 
   DCHECK(outer_contents_frame);
 
@@ -1463,8 +1466,7 @@ void WebContentsImpl::AttachToOuterWebContentsFrame(
   // SiteInstance of the outer WebContents. The proxy will be used to send
   // postMessage to the inner WebContents.
   render_manager->CreateOuterDelegateProxy(
-      outer_contents_frame->GetSiteInstance(),
-      static_cast<RenderFrameHostImpl*>(outer_contents_frame));
+      outer_contents_frame->GetSiteInstance(), outer_contents_frame_impl);
 
   render_manager->SetRWHViewForInnerContents(
       render_manager->GetRenderWidgetHostView());
@@ -1473,6 +1475,11 @@ void WebContentsImpl::AttachToOuterWebContentsFrame(
       render_manager->GetRenderWidgetHostView())
       ->RegisterFrameSinkId();
 
+  if (outer_web_contents_impl->frame_tree_.GetFocusedFrame() ==
+      outer_contents_frame_impl->frame_tree_node()) {
+    SetFocusedFrame(frame_tree_.root(), nullptr);

[alexmos, 2017/03/04 01:12:16]

I'm curious if this makes the code that returns the main frame if there's no
focused frame in GetFocusedFrameIncludingInnerWebContents (that I asked about in
https://codereview.chromium.org/2674353003/diff/60001/content/browser/web_con...)
unnecessary?   This should guarantee that you focus the main frame on attach,
though I'm not sure about the other case you mentioned where the focused frame
can become null.

[avallee, 2017/03/15 02:55:20]

This will end up calling focus on the widget which will cause the renderer side
to focus the main frame when there is no focused frame.

+  }
+
   // Set up the the guest's AX tree to point back at the embedder's AX tree.
   auto* parent_frame = outer_contents_frame->GetParent();
   GetMainFrame()->set_browser_plugin_embedder_ax_tree_id(