OOPIF: Clear old focused frame when focus moves to a cross-process frame.

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 <queue>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 239 matching lines @@
 
 RenderFrameHostImpl* FrameTree::GetMainFrame() const {
   return root_->current_frame_host();
 }
 
 FrameTreeNode* FrameTree::GetFocusedFrame() {
   return FindByID(focused_frame_tree_node_id_);
 }
 
 void FrameTree::SetFocusedFrame(FrameTreeNode* node) {
+  // If the focused frame changed across processes, send a message to the old
+  // focused frame's renderer process to clear focus from that frame and fire
+  // blur events.
+  FrameTreeNode* oldFocusedFrame = GetFocusedFrame();
+  if (oldFocusedFrame &&
+      oldFocusedFrame->current_frame_host()->GetSiteInstance() !=
+          node->current_frame_host()->GetSiteInstance()) {
+    DCHECK(SiteIsolationPolicy::AreCrossProcessFramesPossible());
+    oldFocusedFrame->current_frame_host()->ClearFocus();
+  }
+
   node->set_last_focus_time(base::TimeTicks::Now());
   focused_frame_tree_node_id_ = node->frame_tree_node_id();
 }
 
 void FrameTree::SetFrameRemoveListener(
     const base::Callback<void(RenderFrameHost*)>& on_frame_removed) {
   on_frame_removed_ = on_frame_removed;
 }
 
 RenderViewHostImpl* FrameTree::CreateRenderViewHost(SiteInstance* site_instance,
@@ skipping 122 matching lines @@
   load_progress_ = 0.0;
 }
 
 bool FrameTree::IsLoading() {
   bool is_loading = false;
   ForEach(base::Bind(&IsNodeLoading, &is_loading));
   return is_loading;
 }
 
 }  // namespace content