Fix keyboard focus for OOPIF-<webview>.

content/browser/frame_host/frame_tree.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/frame_host/frame_tree.h"
 
 #include <stddef.h>
 
 #include <queue>
 #include <utility>
@@ skipping 233 matching lines @@
 }
 
 FrameTreeNode* FrameTree::GetFocusedFrame() {
   return FindByID(focused_frame_tree_node_id_);
 }
 
 void FrameTree::SetFocusedFrame(FrameTreeNode* node, SiteInstance* source) {
   if (node == GetFocusedFrame())
     return;
 
+  if (node == nullptr) {

[alexmos, 2016/05/19 00:08:09]

Can you add a comment above this, explaining that we might call this with a null
node when clearing focus for an inner WebContents?

[alexmos, 2016/05/19 00:08:09]

nit: !node

[avallee, 2016/05/24 20:07:07]

Done.

+    if (GetFocusedFrame())
+      GetFocusedFrame()->current_frame_host()->ClearFocusedFrame();
+    focused_frame_tree_node_id_ = FrameTreeNode::kFrameTreeNodeInvalidId;
+
+    // TODO(avallee): https://crbug.com/610795 This line is not sufficient to
+    // make the test pass. There seems to be no focus change events generated.
+    root()->current_frame_host()->UpdateAXTreeData();

[alexmos, 2016/05/19 00:08:09]

Should all three statements in the outer if only happen if (!node &&
GetFocusedFrame())?  Seems like you'd call UpdateAXTreeData redundantly if you
try to clear focus from a FrameTree that already had it cleared.

[avallee, 2016/05/24 20:07:07]

If already nullptr, then:
 if (node == GetFocusedFrame()) 
above would early-out.

+    return;
+  }
+
   std::set<SiteInstance*> frame_tree_site_instances =
       CollectSiteInstances(this);
 
   SiteInstance* current_instance =
       node->current_frame_host()->GetSiteInstance();
 
   // Update the focused frame in all other SiteInstances.  If focus changes to
   // a cross-process frame, this allows the old focused frame's renderer
   // process to clear focus from that frame and fire blur events.  It also
   // ensures that the latest focused frame is available in all renderers to
@@ skipping 162 matching lines @@
   // This is only used to set page-level focus in cross-process subframes, and
   // requests to set focus in main frame's SiteInstance are ignored.
   if (instance != root_manager->current_frame_host()->GetSiteInstance()) {
     RenderFrameProxyHost* proxy =
         root_manager->GetRenderFrameProxyHost(instance);
     proxy->Send(new InputMsg_SetFocus(proxy->GetRoutingID(), is_focused));
   }
 }
 
 }  // namespace content