Prevent unused normal SiteInstances from being used for extensions.

chrome/browser/renderer_host/test/render_process_host_browsertest.cc

 // Copyright (c) 2011 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 "chrome/browser/debugger/devtools_manager.h"
 #include "chrome/browser/renderer_host/site_instance.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
@@ skipping 165 matching lines @@
       devtools, DEVTOOLS_TOGGLE_ACTION_INSPECT);
   host_count++;
   EXPECT_EQ(tab_count, browser()->tab_count());
   EXPECT_EQ(host_count, RenderProcessHostCount());
 }
 
 // When we hit the max number of renderers, verify that the way we do process
 // sharing behaves correctly.  In particular, this test is verifying that even
 // when we hit the max process limit, that renderers of each type will wind up
 // in a process of that type, even if that means creating a new process.
-// TODO(erikkay) crbug.com/43448 - disabled for now until we can get a
-// reasonable implementation in place.
-IN_PROC_BROWSER_TEST_F(RenderProcessHostTest, DISABLED_ProcessOverflow) {
+IN_PROC_BROWSER_TEST_F(RenderProcessHostTest, ProcessOverflow) {
   // Set max renderers to 1 to force running out of processes.
   RenderProcessHost::SetMaxRendererProcessCount(1);
 
   int tab_count = 1;
   int host_count = 1;
   TabContents* tab1 = NULL;
   TabContents* tab2 = NULL;
   RenderProcessHost* rph1 = NULL;
   RenderProcessHost* rph2 = NULL;
   RenderProcessHost* rph3 = NULL;
@@ skipping 57 matching lines @@
   tab_count++;
   host_count++;
   EXPECT_EQ(tab_count, browser()->tab_count());
   tab1 = browser()->GetTabContentsAt(tab_count - 1);
   rph3 = tab1->GetRenderProcessHost();
   EXPECT_EQ(tab1->GetURL(), bookmarks);
   EXPECT_EQ(host_count, RenderProcessHostCount());
   EXPECT_NE(rph1, rph3);
   EXPECT_NE(rph2, rph3);
 }