Disable cross-process navigations in --single-process.

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 <stddef.h>
 
 #include <algorithm>
 #include <string>
@@ skipping 1021 matching lines @@
   return proxy_host;
 }
 
 void RenderFrameHostManager::DeleteRenderFrameProxyHost(
     SiteInstance* site_instance) {
   static_cast<SiteInstanceImpl*>(site_instance)->RemoveObserver(this);
   proxy_hosts_.erase(site_instance->GetId());
 }
 
 bool RenderFrameHostManager::ShouldTransitionCrossSite() {
-  // The logic below is weaker than "are all sites isolated" -- it asks instead,
-  // "is any site isolated". That's appropriate here since we're just trying to
-  // figure out if we're in any kind of site isolated mode, and in which case,
-  // we ignore the kSingleProcess and kProcessPerTab settings.
-  //
-  // TODO(nick): Move all handling of kSingleProcess/kProcessPerTab into
-  // SiteIsolationPolicy so we have a consistent behavior around the interaction
-  // of the process model flags.
-  //
-  // TODO(creis, alexmos): This looks like it will break single-process and
-  // process-per-tab.  See https://crbug.com/688617.
-  if (SiteIsolationPolicy::AreCrossProcessFramesPossible())
-    return true;
-
-  // False in the single-process mode, as it makes RVHs to accumulate
-  // in swapped_out_hosts_.
-  // True if we are using process-per-site-instance (default) or
-  // process-per-site (kProcessPerSite).
-  // TODO(nick): Move handling of kSingleProcess and kProcessPerTab into
-  // SiteIsolationPolicy.
+  // False in single-process mode, which does not support cross-process
+  // navigations or OOPIFs.
   return !base::CommandLine::ForCurrentProcess()->HasSwitch(
-             switches::kSingleProcess) &&
-         !base::CommandLine::ForCurrentProcess()->HasSwitch(
-             switches::kProcessPerTab);
+      switches::kSingleProcess);
 }
 
 bool RenderFrameHostManager::ShouldSwapBrowsingInstancesForNavigation(
     const GURL& current_effective_url,
     bool current_is_view_source_mode,
     SiteInstance* new_site_instance,
     const GURL& new_effective_url,
     bool new_is_view_source_mode) const {
   // A subframe must stay in the same BrowsingInstance as its parent.
   // TODO(nasko): Ensure that SiteInstance swap is still triggered for subframes
@@ skipping 1772 matching lines @@
                       ->is_hidden() != delegate_->IsHidden()) {
     if (delegate_->IsHidden()) {
       view->Hide();
     } else {
       view->Show();
     }
   }
 }
 
 }  // namespace content