Don't swap processes for frames embedded in DevTools pages.

content/browser/frame_host/render_frame_host_manager.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/render_frame_host_manager.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/command_line.h"
@@ skipping 1554 matching lines @@
     const GURL& dest_url) {
   // A transfer is not needed if the current SiteInstance doesn't yet have a
   // site.  This is the case for tests that use NavigateToURL.
   if (!rfh->GetSiteInstance()->HasSite())
     return false;
 
   // We do not currently swap processes for navigations in webview tag guests.
   if (rfh->GetSiteInstance()->GetSiteURL().SchemeIs(kGuestScheme))
     return false;
 
+  // Don't swap processes for extensions embedded in DevTools. See
+  // https://crbug.com/564216.
+  if (rfh->GetSiteInstance()->GetSiteURL().SchemeIs(kChromeDevToolsScheme)) {
+    CHECK(!dest_url.SchemeIs(url::kHttpScheme) &&
+          !dest_url.SchemeIs(url::kHttpsScheme));
+    return false;
+  }
+
   BrowserContext* context = rfh->GetSiteInstance()->GetBrowserContext();
   GURL effective_url = SiteInstanceImpl::GetEffectiveURL(context, dest_url);
 
   // TODO(nasko, nick): These following --site-per-process checks are
   // overly simplistic. Update them to match all the cases
   // considered by DetermineSiteInstanceForURL.
   if (SiteInstance::IsSameWebSite(rfh->GetSiteInstance()->GetBrowserContext(),
                                   rfh->GetSiteInstance()->GetSiteURL(),
                                   dest_url)) {
     return false;  // The same site, no transition needed.
@@ skipping 1062 matching lines @@
 int RenderFrameHostManager::GetOpenerRoutingID(SiteInstance* instance) {
   if (!frame_tree_node_->opener())
     return MSG_ROUTING_NONE;
 
   return frame_tree_node_->opener()
       ->render_manager()
       ->GetRoutingIdForSiteInstance(instance);
 }
 
 }  // namespace content