Delegate decision what site instances can be rendered in what process to chrome

content/browser/tab_contents/render_view_host_manager.cc

 // Copyright (c) 2011 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/tab_contents/render_view_host_manager.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "content/browser/content_browser_client.h"
 #include "content/browser/renderer_host/render_view_host.h"
@@ skipping 330 matching lines @@
   // Check for reasons to swap processes even if we are in a process model that
   // doesn't usually swap (e.g., process-per-tab).
 
   // For security, we should transition between processes when one is a Web UI
   // page and one isn't.  If there's no cur_entry, check the current RVH's
   // site, which might already be committed to a Web UI URL (such as the NTP).
   const GURL& current_url = (cur_entry) ? cur_entry->url() :
       render_view_host_->site_instance()->site();
   content::BrowserContext* browser_context =
       delegate_->GetControllerForRenderManager().browser_context();
+  content::ContentBrowserClient* browser =
+      content::GetContentClient()->browser();
   const content::WebUIFactory* web_ui_factory = content::WebUIFactory::Get();
   if (web_ui_factory->UseWebUIForURL(browser_context, current_url)) {
     // Force swap if it's not an acceptable URL for Web UI.
     if (!web_ui_factory->IsURLAcceptableForWebUI(browser_context,
                                                  new_entry->url()))
       return true;
   } else {
     // Force swap if it's a Web UI URL.
     if (web_ui_factory->UseWebUIForURL(browser_context, new_entry->url()))
       return true;
   }
 
   if (!cur_entry) {
     // Always choose a new process when navigating to extension URLs. The
     // process grouping logic will combine all of a given extension's pages
     // into the same process.
-    if (new_entry->url().SchemeIs(chrome::kExtensionScheme))
+    if (browser->ShouldRunInPrivilegedProcess(new_entry->url()))

[jam, 2011/09/26 21:08:58]

I think this concept of privilieged processes is still hard to understand for
someone reading the content code.

I think it'll be easier if we can ask the embedder if two urls should be run in
the same process. chrome can then compare the urls to see if both are extension
urls or not. Ideally, we would have one function that would do this in
ContentBrowsrClient. Can we use IsSuitableHost() for this purpose?

       return true;
 
     return false;
   }
 
   // We can't switch a RenderView between view source and non-view source mode
   // without screwing up the session history sometimes (when navigating between
   // "view-source:http://foo.com/" and "http://foo.com/", WebKit doesn't treat
   // it as a new navigation). So require a view switch.
   if (cur_entry->IsViewSourceMode() != new_entry->IsViewSourceMode())
     return true;
 
   // Also, we must switch if one is an extension and the other is not the exact
   // same extension.
-  if (cur_entry->url().SchemeIs(chrome::kExtensionScheme) ||
-      new_entry->url().SchemeIs(chrome::kExtensionScheme)) {
+  if (browser->ShouldRunInPrivilegedProcess(cur_entry->url()) ||
+      browser->ShouldRunInPrivilegedProcess(new_entry->url())) {
     if (cur_entry->url().GetOrigin() != new_entry->url().GetOrigin())
       return true;
   }
 
   return false;
 }
 
 SiteInstance* RenderViewHostManager::GetSiteInstanceForEntry(
     const NavigationEntry& entry,
     SiteInstance* curr_instance) {
@@ skipping 494 matching lines @@
   delegate_->NotifySwappedFromRenderManager();
 }
 
 bool RenderViewHostManager::IsSwappedOut(RenderViewHost* rvh) {
   if (!rvh->site_instance())
     return false;
 
   return swapped_out_hosts_.find(rvh->site_instance()->id()) !=
       swapped_out_hosts_.end();
 }