Move existing kSitePerProcess checks to a policy-oracle object

content/browser/loader/cross_site_resource_handler.cc

 // 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.
 
 #include "content/browser/loader/cross_site_resource_handler.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "content/browser/appcache/appcache_interceptor.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/frame_host/cross_site_transferring_request.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/browser/site_instance_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
+#include "content/common/site_isolation_policy.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/global_request_id.h"
 #include "content/public/browser/resource_controller.h"
 #include "content/public/browser/site_instance.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/resource_response.h"
 #include "content/public/common/url_constants.h"
 #include "net/http/http_response_headers.h"
 #include "net/url_request/url_request.h"
@@ skipping 35 matching lines @@
       new CrossSiteTransferringRequest(params.global_request_id));
 
   RenderFrameHostImpl* rfh =
       RenderFrameHostImpl::FromID(params.global_request_id.child_id,
                                   params.render_frame_id);
   if (rfh) {
     if (rfh->GetParent()) {
       // We should only swap processes for subframes in --site-per-process mode.
       // CrossSiteResourceHandler is not installed on subframe requests in
       // default Chrome.
-      CHECK(base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kSitePerProcess));
+      CHECK(SiteIsolationPolicy::AreCrossProcessFramesPossible());
     }
     rfh->OnCrossSiteResponse(
         params.global_request_id, cross_site_transferring_request.Pass(),
         params.transfer_url_chain, params.referrer,
         params.page_transition, params.should_replace_current_entry);
   } else if (leak_requests_for_testing_ && cross_site_transferring_request) {
     // Some unit tests expect requests to be leaked in this case, so they can
     // pass them along manually.
     cross_site_transferring_request->ReleaseRequest();
   }
 }
 
 // Returns whether a transfer is needed by doing a check on the UI thread.
 bool CheckNavigationPolicyOnUI(GURL url, int process_id, int render_frame_id) {
-  CHECK(base::CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kSitePerProcess));
+  CHECK(SiteIsolationPolicy::AreCrossProcessFramesPossible());
   RenderFrameHostImpl* rfh =
       RenderFrameHostImpl::FromID(process_id, render_frame_id);
   if (!rfh)
     return false;
 
   // A transfer is not needed if the current SiteInstance doesn't yet have a
   // site.  This is the case for tests that use NavigateToURL.
   if (!rfh->GetSiteInstance()->HasSite())
     return false;
 
   // For now, GuestViews never transfer on cross-site navigations.
   WebContentsImpl* web_contents =
       static_cast<WebContentsImpl*>(WebContents::FromRenderFrameHost(rfh));
   if (web_contents->GetBrowserPluginGuest())
     return false;
 
-  // TODO(nasko): This check is very simplistic and is used temporarily only
-  // for --site-per-process. It should be updated to match the check performed
-  // by RenderFrameHostManager::UpdateStateForNavigate.
-  return !SiteInstance::IsSameWebSite(
-      rfh->GetSiteInstance()->GetBrowserContext(),
-      rfh->GetSiteInstance()->GetSiteURL(), url);
+  // TODO(nasko, nick): These following --site-per-process checks are
+  // overly simplistic. Update them to match all the cases
+  // considered by RenderFrameHostManager::DetermineSiteInstanceForURL.
+  if (SiteInstance::IsSameWebSite(rfh->GetSiteInstance()->GetBrowserContext(),
+                                  rfh->GetSiteInstance()->GetSiteURL(), url)) {
+    return false;  // The same site, no transition needed.
+  }
+
+  // The sites differ. If either one requires a dedicated process,
+  // then a transfer is needed.
+  return rfh->GetSiteInstance()->RequiresDedicatedProcess() ||
+         SiteIsolationPolicy::DoesSiteRequireDedicatedProcess(url);
 }
 
 }  // namespace
 
 CrossSiteResourceHandler::CrossSiteResourceHandler(
     scoped_ptr<ResourceHandler> next_handler,
     net::URLRequest* request)
     : LayeredResourceHandler(request, next_handler.Pass()),
       has_started_response_(false),
       in_cross_site_transition_(false),
@@ skipping 34 matching lines @@
     ResourceResponse* response,
     bool* defer) {
   // At this point, we know that the response is safe to send back to the
   // renderer: it is not a download, and it has passed the SSL and safe
   // browsing checks.
   // We should not have already started the transition before now.
   DCHECK(!in_cross_site_transition_);
 
   ResourceRequestInfoImpl* info = GetRequestInfo();
 
-  // We only need to pause the response if a transfer to a different process is
-  // required.  Other cross-process navigations can proceed immediately, since
-  // we run the unload handler at commit time.
-  // Note that a process swap may no longer be necessary if we transferred back
-  // into the original process due to a redirect.
-  bool should_transfer =
+  // The content embedder can decide that a transfer to a different process is
+  // required for this URL.  If so, pause the response now.  Other cross process
+  // navigations can proceed immediately, since we run the unload handler at
+  // commit time.  Note that a process swap may no longer be necessary if we
+  // transferred back into the original process due to a redirect.
+  bool definitely_transfer =
       GetContentClient()->browser()->ShouldSwapProcessesForRedirect(
           info->GetContext(), request()->original_url(), request()->url());
 
   // If this is a download, just pass the response through without doing a
   // cross-site check.  The renderer will see it is a download and abort the
   // request.
   //
   // Similarly, HTTP 204 (No Content) responses leave us showing the previous
   // page.  We should allow the navigation to finish without running the unload
   // handler or swapping in the pending RenderFrameHost.
   //
   // In both cases, any pending RenderFrameHost (if one was created for this
   // navigation) will stick around until the next cross-site navigation, since
   // we are unable to tell when to destroy it.
   // See RenderFrameHostManager::RendererAbortedProvisionalLoad.
   //
   // TODO(davidben): Unify IsDownload() and is_stream(). Several places need to
   // check for both and remembering about streams is error-prone.
   if (info->IsDownload() || info->is_stream() ||
       (response->head.headers.get() &&
        response->head.headers->response_code() == 204)) {
     return next_handler_->OnResponseStarted(response, defer);
   }
 
-  // When the --site-per-process flag is passed, we transfer processes for
-  // cross-site navigations. This is skipped if a transfer is already required
-  // or for WebUI processes for now, since pages like the NTP host multiple
-  // cross-site WebUI iframes.
-  if (!should_transfer &&
-      base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kSitePerProcess) &&
+  if (definitely_transfer) {
+    // Now that we know a transfer is needed and we have something to commit, we
+    // pause to let the UI thread set up the transfer.
+    StartCrossSiteTransition(response);
+
+    // Defer loading until after the new renderer process has issued a
+    // corresponding request.
+    *defer = true;
+    OnDidDefer();
+    return true;
+  }
+
+  // In the site-per-process model, we may also decide (independently from the
+  // content embedder's ShouldSwapProcessesForRedirect decision above) that a
+  // process transfer is needed.  For that we need to consult the navigation
+  // policy on the UI thread, so pause the response.  Process transfers are
+  // skipped for WebUI processes for now, since e.g. chrome://settings has
+  // multiple "cross-site" chrome:// frames, and that doesn't yet work cross-
+  // process.
+  if (SiteIsolationPolicy::AreCrossProcessFramesPossible() &&
       !ChildProcessSecurityPolicyImpl::GetInstance()->HasWebUIBindings(
           info->GetChildID())) {
     return DeferForNavigationPolicyCheck(info, response, defer);
   }
 
-  if (!should_transfer)
-    return next_handler_->OnResponseStarted(response, defer);
-
-  // Now that we know a transfer is needed and we have something to commit, we
-  // pause to let the UI thread set up the transfer.
-  StartCrossSiteTransition(response);
-
-  // Defer loading until after the new renderer process has issued a
-  // corresponding request.
-  *defer = true;
-  OnDidDefer();
-  return true;
+  // No deferral needed. Pass the response through.
+  return next_handler_->OnResponseStarted(response, defer);
 }
 
 void CrossSiteResourceHandler::ResumeOrTransfer(bool is_transfer) {
   if (is_transfer) {
     StartCrossSiteTransition(response_.get());
   } else {
     ResumeResponse();
   }
 }
 
@@ skipping 146 matching lines @@
     controller()->Resume();
   }
 }
 
 void CrossSiteResourceHandler::OnDidDefer() {
   did_defer_ = true;
   request()->LogBlockedBy("CrossSiteResourceHandler");
 }
 
 }  // namespace content