Fix keyboard focus for OOPIF-<webview>.

content/browser/frame_host/frame_tree.cc

Index: content/browser/frame_host/frame_tree.cc
diff --git a/content/browser/frame_host/frame_tree.cc b/content/browser/frame_host/frame_tree.cc
index 9977976aaba40eb87ec1c970367ba9b3f85a4053..6a601f07867dcbf7d034fd5d720f860a9162dc18 100644
--- a/content/browser/frame_host/frame_tree.cc
+++ b/content/browser/frame_host/frame_tree.cc
@@ -251,6 +251,15 @@ void FrameTree::SetFocusedFrame(FrameTreeNode* node, SiteInstance* source) {
   if (node == GetFocusedFrame())
     return;
 
+  if (node == nullptr) {
+    if (GetFocusedFrame()) {

[lfg, 2016/05/06 21:23:33]

Nit: no need for {}.

[avallee, 2016/05/11 18:26:11]

Done.

+      GetFocusedFrame()->current_frame_host()->UnsetFocusedFrame();
+    }
+    focused_frame_tree_node_id_ = FrameTreeNode::kFrameTreeNodeInvalidId;
+    // FIXME: Do we need to update the AX tree here?

[lfg, 2016/05/06 21:23:33]

Check with dmazzoni@ if this is necessary.

[dmazzoni, 2016/05/09 17:07:20]

Yes, it'd be good to add this line (just like is done at the bottom of this
function):

root()->current_frame_host()->UpdateAXTreeData();

[avallee, 2016/05/11 18:26:11]

Sent email.

[avallee, 2016/05/11 18:26:11]

This doesn't seem to make the test pass. I've filed a bug.

+    return;
+  }
+
   std::set<SiteInstance*> frame_tree_site_instances =
       CollectSiteInstances(this);
 
@@ -272,13 +281,15 @@ void FrameTree::SetFocusedFrame(FrameTreeNode* node, SiteInstance* source) {
       DCHECK(SiteIsolationPolicy::AreCrossProcessFramesPossible());
       RenderFrameProxyHost* proxy =
           node->render_manager()->GetRenderFrameProxyHost(instance);
-      proxy->SetFocusedFrame();
+      if (proxy) {

[lfg, 2016/05/06 21:23:32]

nit: {}

[avallee, 2016/05/11 18:26:11]

Done.

+        proxy->SetFocusedFrame();
+      }
     }
   }
 
   // If |node| was focused from a cross-process frame (i.e., via
   // window.focus()), tell its RenderFrame that it should focus.
-  if (current_instance != source)
+  if (current_instance && current_instance != source)
     node->current_frame_host()->SetFocusedFrame();
 
   focused_frame_tree_node_id_ = node->frame_tree_node_id();