PlzNavigate: Speculatively spawns a renderer process for navigations.

content/browser/site_instance_impl.h

 // 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.
 
 #ifndef CONTENT_BROWSER_SITE_INSTANCE_IMPL_H_
 #define CONTENT_BROWSER_SITE_INSTANCE_IMPL_H_
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/render_process_host_observer.h"
@@ skipping 66 matching lines @@
 
   // Get the effective URL for the given actual URL.  This allows the
   // ContentBrowserClient to override the SiteInstance's site for certain URLs.
   // For example, Chrome uses this to replace hosted app URLs with extension
   // hosts.
   // Only public so that we can make a consistent process swap decision in
   // RenderFrameHostManager.
   static GURL GetEffectiveURL(BrowserContext* browser_context,
                               const GURL& url);
 
+  // Creates a new related SiteInstance that is not bound to a URL.
+  // Note: use with care! When setting the URL later on for if it already exists
+  // within the browsing instance that will lead to inconsistencies.
+  SiteInstance* GetRelatedEmptySiteInstance();
+
  protected:
   friend class BrowsingInstance;
   friend class SiteInstance;
 
   // Virtual to allow tests to extend it.
   ~SiteInstanceImpl() override;
 
   // Create a new SiteInstance.  Protected to give access to BrowsingInstance
   // and tests; most callers should use Create or GetRelatedSiteInstance
   // instead.
@@ skipping 32 matching lines @@
 
   // Whether SetSite has been called.
   bool has_site_;
 
   DISALLOW_COPY_AND_ASSIGN(SiteInstanceImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SITE_INSTANCE_IMPL_H_