New WebContents created via ctrl-click should be in a new process.

chrome/browser/extensions/api/tabs/tabs_api.cc

Index: chrome/browser/extensions/api/tabs/tabs_api.cc
diff --git a/chrome/browser/extensions/api/tabs/tabs_api.cc b/chrome/browser/extensions/api/tabs/tabs_api.cc
index e4ec50d3ce1cbe127880073ff250eaddf86ab6fd..30ae516d6381709c9ed6c62edd6cd72fddb4abc3 100644
--- a/chrome/browser/extensions/api/tabs/tabs_api.cc
+++ b/chrome/browser/extensions/api/tabs/tabs_api.cc
@@ -621,8 +621,13 @@ ExtensionFunction::ResponseAction WindowsCreateFunction::Run() {
     chrome::NavigateParams navigate_params(new_window, url,
                                            ui::PAGE_TRANSITION_LINK);
     navigate_params.disposition = WindowOpenDisposition::NEW_FOREGROUND_TAB;
+
+    // Make sure that (if possible) the new contents are created in the same
+    // renderer process as the caller of the chrome.windows.create API.
+    navigate_params.use_new_renderer_for_new_contents = false;
     navigate_params.source_site_instance =
         render_frame_host()->GetSiteInstance();
+
     chrome::Navigate(&navigate_params);
   }