Fix process reuse for dedicated processes when over process limit.

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 <stddef.h>
 #include <stdint.h>
 
@@ skipping 131 matching lines @@
   static GURL GetEffectiveURL(BrowserContext* browser_context,
                               const GURL& url);
 
   // Returns true if pages loaded from |url| ought to be handled only by a
   // renderer process isolated from other sites. If --site-per-process is on the
   // command line, this is true for all sites. In other site isolation modes,
   // only a subset of sites will require dedicated processes.
   static bool DoesSiteRequireDedicatedProcess(BrowserContext* browser_context,
                                               const GURL& url);
 
+  // Returns true if a process for |site_url| should be locked to just that
+  // site.  Returning true here also implies that |site_url| requires a
+  // dedicated process.  However, the converse does not hold: this might still
+  // return false for certain special cases where an origin lock can't be
+  // applied even when |site_url| requires a dedicated process (e.g., with
+  // --site-per-process).  Examples of those cases include <webview> guests,
+  // WebUI, or extensions where a process is currently allowed to be reused for
+  // different extensions.  Most of these special cases should eventually be
+  // removed, and this function should become equivalent to
+  // DoesSiteRequireDedicatedProcess().
+  static bool ShouldLockToOrigin(BrowserContext* browser_context,
+                                 GURL site_url);
+
  private:
   friend class BrowsingInstance;
   friend class SiteInstanceTestBrowserClient;
 
   // Create a new SiteInstance.  Only BrowsingInstance should call this
   // directly; clients should use Create() or GetRelatedSiteInstance() instead.
   explicit SiteInstanceImpl(BrowsingInstance* browsing_instance);
 
   ~SiteInstanceImpl() override;
 
   // RenderProcessHostObserver implementation.
   void RenderProcessHostDestroyed(RenderProcessHost* host) override;
   void RenderProcessWillExit(RenderProcessHost* host) override;
   void RenderProcessExited(RenderProcessHost* host,
                            base::TerminationStatus status,
                            int exit_code) override;
 
   // Used to restrict a process' origin access rights.
-  void LockToOrigin();
+  void LockToOriginIfNeeded();
 
   // This gets the render process to use for default subframe site instances.
   RenderProcessHost* GetDefaultSubframeProcessHost(
       BrowserContext* browser_context,
       bool is_for_guests_only);
 
   // An object used to construct RenderProcessHosts.
   static const RenderProcessHostFactory* g_render_process_host_factory_;
 
   // The next available SiteInstance ID.
@@ skipping 25 matching lines @@
   ProcessReusePolicy process_reuse_policy_;
 
   base::ObserverList<Observer, true> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(SiteInstanceImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SITE_INSTANCE_IMPL_H_