Do not create proxy hosts in the subtree of navigating frame.

content/browser/frame_host/frame_tree_browsertest.cc

 // Copyright 2014 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 "base/command_line.h"
 #include "content/browser/frame_host/frame_tree.h"
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/notification_service.h"
@@ skipping 229 matching lines @@
   GURL::Replacements replace_host;
   std::string foo_com("foo.com");
 
   // Load cross-site page into iframe.
   GURL cross_site_url(test_server()->GetURL("files/title2.html"));
   replace_host.SetHostStr(foo_com);
   cross_site_url = cross_site_url.ReplaceComponents(replace_host);
   NavigateFrameToURL(root->child_at(0), cross_site_url);
 
   // Ensure that we have created a new process for the subframe.
-  ASSERT_EQ(1U, root->child_count());
+  ASSERT_EQ(2U, root->child_count());
   FrameTreeNode* child = root->child_at(0);
   SiteInstance* child_instance = child->current_frame_host()->GetSiteInstance();
   RenderViewHost* rvh = child->current_frame_host()->render_view_host();
   RenderProcessHost* rph = child->current_frame_host()->GetProcess();
 
   EXPECT_NE(shell()->web_contents()->GetRenderViewHost(), rvh);
   EXPECT_NE(shell()->web_contents()->GetSiteInstance(), child_instance);
   EXPECT_NE(shell()->web_contents()->GetRenderProcessHost(), rph);
 
   // Ensure that the root node has a proxy for the child node's SiteInstance.
@@ skipping 10 matching lines @@
   // Ensure that the RenderViews and RenderFrames are all live.
   EXPECT_TRUE(
       root->current_frame_host()->render_view_host()->IsRenderViewLive());
   EXPECT_TRUE(
       child->current_frame_host()->render_view_host()->IsRenderViewLive());
   EXPECT_TRUE(root->current_frame_host()->IsRenderFrameLive());
   EXPECT_TRUE(root->child_at(0)->current_frame_host()->IsRenderFrameLive());
 }
 
 }  // namespace content