Enable swapping a frame back in to its parent process

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 "base/command_line.h"
 #include "base/strings/stringprintf.h"
 #include "content/browser/frame_host/cross_process_frame_connector.h"
 #include "content/browser/frame_host/frame_tree.h"
@@ skipping 319 matching lines @@
 
   // Check again that a new process is created and is different from the
   // top level one and the previous one.
   ASSERT_EQ(2U, root->child_count());
   child = root->child_at(0);
   EXPECT_NE(shell()->web_contents()->GetSiteInstance(),
             child->current_frame_host()->GetSiteInstance());
   EXPECT_NE(site_instance,
             child->current_frame_host()->GetSiteInstance());
 
-  // TODO(japhet): This currently causes an assertion in the renderer process.
-  // Enable when the assertion is fixed.
-  //NavigateFrameToURL(child, http_url);
-  //EXPECT_EQ(http_url, observer.navigation_url());
-  //EXPECT_TRUE(observer.navigation_succeeded());
-  //EXPECT_EQ(shell()->web_contents()->GetSiteInstance(),
-  //          child->current_frame_host()->GetSiteInstance());
+  // Navigate back to the parent's origin and ensure we return to the
+  // parent's process.
+  NavigateFrameToURL(child, http_url);
+  EXPECT_EQ(http_url, observer.navigation_url());
+  EXPECT_TRUE(observer.navigation_succeeded());
+  EXPECT_EQ(shell()->web_contents()->GetSiteInstance(),
+            child->current_frame_host()->GetSiteInstance());
 }
 
 // Crash a subframe and ensures its children are cleared from the FrameTree.
 // See http://crbug.com/338508.
 // TODO(creis): Disabled for flakiness; see http://crbug.com/405582.
 // TODO(creis): Enable this on Android when we can kill the process there.
 IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, DISABLED_CrashSubframe) {
   GURL main_url(embedded_test_server()->GetURL("/site_per_process_main.html"));
   NavigateToURL(shell(), main_url);
 
@@ skipping 372 matching lines @@
     }
 
     navigation_observer.Wait();
     EXPECT_TRUE(observer.navigation_succeeded());
     EXPECT_EQ(cross_site_url, observer.navigation_url());
     EXPECT_EQ(0U, child->child_count());
   }
 }
 
 }  // namespace content