Check BrowsingInstance before swapping prerenders.

content/browser/frame_host/render_frame_host_manager.cc

 // Copyright 2013 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/frame_host/render_frame_host_manager.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 70 matching lines @@
       weak_factory_(this) {}
 
 RenderFrameHostManager::~RenderFrameHostManager() {
   if (pending_render_frame_host_)
     CancelPending();
 
   if (cross_process_frame_connector_)
     delete cross_process_frame_connector_;
 
   // We should always have a current RenderFrameHost except in some tests.
-  render_frame_host_.reset();
+  SetRenderFrameHost(scoped_ptr<RenderFrameHostImpl>());
 
   // Delete any swapped out RenderFrameHosts.
   for (RenderFrameProxyHostMap::iterator iter = proxy_hosts_.begin();
        iter != proxy_hosts_.end();
        ++iter) {
     delete iter->second;
   }
 }
 
 void RenderFrameHostManager::Init(BrowserContext* browser_context,
                                   SiteInstance* site_instance,
                                   int view_routing_id,
                                   int frame_routing_id) {
   // Create a RenderViewHost and RenderFrameHost, once we have an instance.  It
   // is important to immediately give this SiteInstance to a RenderViewHost so
   // that the SiteInstance is ref counted.
   if (!site_instance)
     site_instance = SiteInstance::Create(browser_context);
 
-  render_frame_host_ = CreateRenderFrameHost(site_instance,
-                                             view_routing_id,
-                                             frame_routing_id,
-                                             false,
-                                             delegate_->IsHidden());
+  SetRenderFrameHost(CreateRenderFrameHost(site_instance,
+                                           view_routing_id,
+                                           frame_routing_id,
+                                           false,
+                                           delegate_->IsHidden()));
 
   // Keep track of renderer processes as they start to shut down or are
   // crashed/killed.
   registrar_.Add(this, NOTIFICATION_RENDERER_PROCESS_CLOSED,
                  NotificationService::AllSources());
   registrar_.Add(this, NOTIFICATION_RENDERER_PROCESS_CLOSING,
                  NotificationService::AllSources());
 }
 
 RenderViewHostImpl* RenderFrameHostManager::current_host() const {
@@ skipping 895 matching lines @@
       render_frame_host_->render_view_host()->GetView() &&
       render_frame_host_->render_view_host()->GetView()->HasFocus();
 
   // TODO(creis): As long as show/hide are on RVH, we don't want to do them for
   // subframe navigations or they'll interfere with the top-level page.
   bool is_main_frame = frame_tree_node_->IsMainFrame();
 
   // Swap in the pending frame and make it active. Also ensure the FrameTree
   // stays in sync.
   scoped_ptr<RenderFrameHostImpl> old_render_frame_host =
-      render_frame_host_.Pass();
-  render_frame_host_ = pending_render_frame_host_.Pass();
+      SetRenderFrameHost(pending_render_frame_host_.Pass());
   if (is_main_frame)
     render_frame_host_->render_view_host()->AttachToFrameTree();
 
   // The process will no longer try to exit, so we can decrement the count.
   render_frame_host_->GetProcess()->RemovePendingView();
 
   // If the view is gone, then this RenderViewHost died while it was hidden.
   // We ignored the RenderProcessGone call at the time, so we should send it now
   // to make sure the sad tab shows up, etc.
   if (!render_frame_host_->render_view_host()->GetView()) {
@@ skipping 311 matching lines @@
         pending_render_frame_host.Pass());
   } else {
     // We won't be coming back, so delete this one.
     pending_render_frame_host.reset();
   }
 
   pending_web_ui_.reset();
   pending_and_current_web_ui_.reset();
 }
 
+scoped_ptr<RenderFrameHostImpl> RenderFrameHostManager::SetRenderFrameHost(
+    scoped_ptr<RenderFrameHostImpl> render_frame_host) {
+  // Swap the two.
+  scoped_ptr<RenderFrameHostImpl> old_render_frame_host =
+      render_frame_host_.Pass();
+  render_frame_host_ = render_frame_host.Pass();
+
+  if (frame_tree_node_->IsMainFrame()) {
+    // Update the count of WebContents objects using this SiteInstance.  All
+    // subframes are in the same BrowsingInstance as the main frame, so we only
+    // do this for the top-level frame.  This makes the value easier for
+    // consumers to interpret.
+    if (render_frame_host_) {
+      static_cast<SiteInstanceImpl*>(render_frame_host_->GetSiteInstance())->
+          IncrementRelatedActiveContentsCount();
+    }
+    if (old_render_frame_host) {
+      static_cast<SiteInstanceImpl*>(old_render_frame_host->GetSiteInstance())->
+          DecrementRelatedActiveContentsCount();
+    }
+  }
+
+  return old_render_frame_host.Pass();
+}
+
 void RenderFrameHostManager::RenderViewDeleted(RenderViewHost* rvh) {
   // We are doing this in order to work around and to track a crasher
   // (http://crbug.com/23411) where it seems that pending_render_frame_host_ is
   // deleted (not sure from where) but not NULLed.
   if (pending_render_frame_host_ &&
       rvh == pending_render_frame_host_->render_view_host()) {
     // If you hit this NOTREACHED, please report it in the following bug
     // http://crbug.com/23411 Make sure to include what you were doing when it
     // happened  (navigating to a new page, closing a tab...) and if you can
     // reproduce.
@@ skipping 51 matching lines @@
     SiteInstance* instance) const {
   RenderFrameProxyHostMap::const_iterator iter =
       proxy_hosts_.find(instance->GetId());
   if (iter != proxy_hosts_.end())
     return iter->second;
 
   return NULL;
 }
 
 }  // namespace content