Destroy the old RenderWidgetHostView when swapping out a main frame.

content/browser/site_per_process_browsertest.cc

 // Copyright (c) 2012 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/site_per_process_browsertest.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 8544 matching lines @@
   // |popup2|. This is allowed since the main tab is |popup2|'s opener.
   EXPECT_TRUE(NavigateToURL(shell(), b_url));
 
   base::string16 expected_title(base::UTF8ToUTF16("foo"));
   TitleWatcher title_watcher(popup2->web_contents(), expected_title);
   EXPECT_TRUE(ExecuteScript(
       shell(), "window.open('','popup2').postMessage('foo', '*');"));
   EXPECT_EQ(expected_title, title_watcher.WaitAndGetTitle());
 }
 
+// This tests that we don't hide the RenderViewHost when reusing the
+// RenderViewHost for a subframe. See https://crbug.com/638375.
+IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, ReusedRenderViewNotHidden) {
+  GURL a_url(embedded_test_server()->GetURL("a.com", "/title1.html"));
+  GURL b_url_a_subframe(embedded_test_server()->GetURL(
+      "b.com", "/cross_site_iframe_factory.html?b(a)"));
+
+  EXPECT_TRUE(NavigateToURL(shell(), a_url));
+
+  // Open a popup in a.com.
+  Shell* popup = OpenPopup(shell(), a_url, "popup");
+
+  // Navigate this popup to b.com with an a.com subframe.
+  EXPECT_TRUE(NavigateToURL(popup, b_url_a_subframe));
+
+  FrameTreeNode* root = static_cast<WebContentsImpl*>(popup->web_contents())
+                            ->GetFrameTree()
+                            ->root();
+  FrameTreeNode* child_node = root->child_at(0);
+
+  EXPECT_FALSE(child_node->current_frame_host()
+                   ->render_view_host()
+                   ->GetWidget()
+                   ->is_hidden());
+}
+
 }  // namespace content