Remove swapped-out usage in --site-per-process.

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/logging.h"
@@ skipping 186 matching lines @@
 
   // If the current render_frame_host_ isn't live, we should create it so
   // that we don't show a sad tab while the dest_render_frame_host fetches
   // its first page.  (Bug 1145340)
   if (dest_render_frame_host != render_frame_host_ &&
       !render_frame_host_->IsRenderFrameLive()) {
     // Note: we don't call InitRenderView here because we are navigating away
     // soon anyway, and we don't have the NavigationEntry for this host.
     delegate_->CreateRenderViewForRenderManager(
         render_frame_host_->render_view_host(), MSG_ROUTING_NONE,
-        MSG_ROUTING_NONE, frame_tree_node_->IsMainFrame());
+        MSG_ROUTING_NONE, frame_tree_node_->current_replication_state(),
+        frame_tree_node_->IsMainFrame());
   }
 
   // If the renderer crashed, then try to create a new one to satisfy this
   // navigation request.
   if (!dest_render_frame_host->IsRenderFrameLive()) {
     // Instruct the destination render frame host to set up a Mojo connection
     // with the new render frame if necessary.  Note that this call needs to
     // occur before initializing the RenderView; the flow of creating the
     // RenderView can cause browser-side code to execute that expects the this
     // RFH's ServiceRegistry to be initialized (e.g., if the site is a WebUI
@@ skipping 384 matching lines @@
       old_render_frame_host->render_view_host(), frame_tree_node_);
   CHECK(proxy_hosts_.insert(std::make_pair(old_site_instance_id, proxy)).second)
       << "Inserting a duplicate item.";
 
   // Tell the old RenderFrameHost to swap out and be replaced by the proxy.
   old_render_frame_host->SwapOut(proxy, true);
 
   // SwapOut creates a RenderFrameProxy, so set the proxy to be initialized.
   proxy->set_render_frame_proxy_created(true);
 
-  bool is_main_frame = frame_tree_node_->IsMainFrame();
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kSitePerProcess) &&
-      !is_main_frame) {
-    // In --site-per-process, subframes delete their RFH rather than storing it
+          switches::kSitePerProcess)) {
+    // In --site-per-process, frames delete their RFH rather than storing it
     // in the proxy.  Schedule it for deletion once the SwapOutACK comes in.
     // TODO(creis): This will be the default when we remove swappedout://.
     MoveToPendingDeleteHosts(old_render_frame_host.Pass());
   } else {
     // We shouldn't get here for subframes, since we only swap subframes when
     // --site-per-process is used.
-    DCHECK(is_main_frame);
+    DCHECK(frame_tree_node_->IsMainFrame());
 
     // The old RenderFrameHost will stay alive inside the proxy so that existing
     // JavaScript window references to it stay valid.
     proxy->TakeFrameHostOwnership(old_render_frame_host.Pass());
   }
 }
 
 void RenderFrameHostManager::DiscardUnusedFrame(
     scoped_ptr<RenderFrameHostImpl> render_frame_host) {
   // TODO(carlosk): this code is very similar to what can be found in
   // SwapOutOldFrame and we should see that these are unified at some point.
 
   // If the SiteInstance for the pending RFH is being used by others don't
   // delete the RFH. Just swap it out and it can be reused at a later point.
+  // In --site-per-process, RenderFrameHosts are not kept around and are
+  // deleted when not used, replaced by RenderFrameProxyHosts.
   SiteInstanceImpl* site_instance = render_frame_host->GetSiteInstance();
   if (site_instance->HasSite() && site_instance->active_frame_count() > 1) {
     // Any currently suspended navigations are no longer needed.
     render_frame_host->CancelSuspendedNavigations();
 
     CHECK(!GetRenderFrameProxyHost(site_instance));
     RenderFrameProxyHost* proxy = new RenderFrameProxyHost(
         site_instance, render_frame_host->render_view_host(), frame_tree_node_);
     proxy_hosts_[site_instance->GetId()] = proxy;
 
     // Check if the RenderFrameHost is already swapped out, to avoid swapping it
     // out again.
     if (!render_frame_host->is_swapped_out())
       render_frame_host->SwapOut(proxy, false);
 
-    if (frame_tree_node_->IsMainFrame())
+    if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kSitePerProcess)) {
+      DCHECK(frame_tree_node_->IsMainFrame());
       proxy->TakeFrameHostOwnership(render_frame_host.Pass());
-  } else {
+    }
+  }
+
+  if (render_frame_host) {
     // We won't be coming back, so delete this one.
     ShutdownProxiesIfLastActiveFrameInSiteInstance(render_frame_host.get());
     render_frame_host.reset();
   }
 }
 
 void RenderFrameHostManager::MoveToPendingDeleteHosts(
     scoped_ptr<RenderFrameHostImpl> render_frame_host) {
   // |render_frame_host| will be deleted when its SwapOut ACK is received, or
   // when the timer times out, or when the RFHM itself is deleted (whichever
@@ skipping 247 matching lines @@
   RenderFrameProxyHostMap::iterator iter =
       node->render_manager()->proxy_hosts_.find(site_instance_id);
   if (iter != node->render_manager()->proxy_hosts_.end()) {
     RenderFrameProxyHost* proxy = iter->second;
     // Delete the proxy.  If it is for a main frame (and thus the RFH is stored
     // in the proxy) and it was still pending swap out, move the RFH to the
     // pending deletion list first.
     if (node->IsMainFrame() &&
         proxy->render_frame_host() &&
         proxy->render_frame_host()->rfh_state() ==
-        RenderFrameHostImpl::STATE_PENDING_SWAP_OUT) {
+            RenderFrameHostImpl::STATE_PENDING_SWAP_OUT) {
+      DCHECK(!base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kSitePerProcess));
       scoped_ptr<RenderFrameHostImpl> swapped_out_rfh =
           proxy->PassFrameHostOwnership();
       node->render_manager()->MoveToPendingDeleteHosts(swapped_out_rfh.Pass());
     }
     delete proxy;
     node->render_manager()->proxy_hosts_.erase(site_instance_id);
   }
 
   return true;
 }
@@ skipping 517 matching lines @@
   return true;
 }
 
 scoped_ptr<RenderFrameHostImpl> RenderFrameHostManager::CreateRenderFrame(
     SiteInstance* instance,
     WebUIImpl* web_ui,
     int opener_route_id,
     int flags,
     int* view_routing_id_ptr) {
   bool swapped_out = !!(flags & CREATE_RF_SWAPPED_OUT);
+  bool is_site_per_process = base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kSitePerProcess);
+
   CHECK(instance);
+  CHECK_IMPLIES(is_site_per_process, !swapped_out);
+
   // Swapped out views should always be hidden.
-  DCHECK(!swapped_out || (flags & CREATE_RF_HIDDEN));
-
-  // TODO(nasko): Remove the following CHECK once cross-process navigation no
-  // longer relies on swapped out RFH for the top-level frame.
-  if (!frame_tree_node_->IsMainFrame())
-    CHECK(!swapped_out);
+  DCHECK_IMPLIES(swapped_out, (flags & CREATE_RF_HIDDEN));
 
   scoped_ptr<RenderFrameHostImpl> new_render_frame_host;
   bool success = true;
   if (view_routing_id_ptr)
     *view_routing_id_ptr = MSG_ROUTING_NONE;
 
   // We are creating a pending, speculative or swapped out RFH here. We should
   // never create it in the same SiteInstance as our current RFH.
   CHECK_NE(render_frame_host_->GetSiteInstance(), instance);
 
   // Check if we've already created an RFH for this SiteInstance.  If so, try
   // to re-use the existing one, which has already been initialized.  We'll
   // remove it from the list of proxy hosts below if it will be active.
   RenderFrameProxyHost* proxy = GetRenderFrameProxyHost(instance);
   if (proxy && proxy->render_frame_host()) {
+    CHECK(!is_site_per_process);
     if (view_routing_id_ptr)
       *view_routing_id_ptr = proxy->GetRenderViewHost()->GetRoutingID();
     // Delete the existing RenderFrameProxyHost, but reuse the RenderFrameHost.
     // Prevent the process from exiting while we're trying to use it.
     if (!swapped_out) {
       new_render_frame_host = proxy->PassFrameHostOwnership();
       new_render_frame_host->GetProcess()->AddPendingView();
 
       proxy_hosts_.erase(instance->GetId());
       delete proxy;
@@ skipping 26 matching lines @@
       // Remember that InitRenderView also created the RenderFrameProxy.
       if (swapped_out)
         proxy->set_render_frame_proxy_created(true);
       if (frame_tree_node_->IsMainFrame()) {
         // Don't show the main frame's view until we get a DidNavigate from it.
         // Only the RenderViewHost for the top-level RenderFrameHost has a
         // RenderWidgetHostView; RenderWidgetHosts for out-of-process iframes
         // will be created later and hidden.
         if (render_view_host->GetView())
           render_view_host->GetView()->Hide();
-      } else if (!swapped_out) {
+      }
+      // With --site-per-process, RenderViewHost for |instance| might exist
+      // prior to calling CreateRenderFrame, due to a subframe in
+      // |instance|. In such a case, InitRenderView will not create the
+      // RenderFrame in the renderer process and it needs to be done
+      // explicitly.
+      if (is_site_per_process) {

[Charlie Reis, 2015/06/04 22:27:31]

Thanks.  The explanation helped, but it's still tricky to reason about the
change, given the three conditions involved (2^3=8 paths through the code to
consider) plus the removal of the else block.

After mapping them all out, it looks like one path matters: main frame +
!swapped_out + site-per-process = Hide + InitRenderFrame.  

However one other path is different, and it might be concerning: subframe +
!swapped_out + default mode.  This used to call InitRenderFrame, but now it does
nothing.  Maybe this is ok if we never get to this method in default mode? 
(i.e., We always create subframe RenderFrames in the renderer process.)

[nasko, 2015/06/04 23:38:36]

We should never be calling this method for default chrome and subframe. I've
added a CHECK at the beginning of the method to ensure that's the case.

[Charlie Reis, 2015/06/05 18:28:45]

Acknowledged.

         // Init the RFH, so a RenderFrame is created in the renderer.
         DCHECK(new_render_frame_host);
         success = InitRenderFrame(new_render_frame_host.get());
       }
     }
 
     if (success) {
       if (view_routing_id_ptr)
         *view_routing_id_ptr = render_view_host->GetRoutingID();
     }
@@ skipping 21 matching lines @@
   }
   return nullptr;
 }
 
 int RenderFrameHostManager::CreateRenderFrameProxy(SiteInstance* instance) {
   // A RenderFrameProxyHost should never be created in the same SiteInstance as
   // the current RFH.
   CHECK(instance);
   CHECK_NE(instance, render_frame_host_->GetSiteInstance());
 
+  bool is_site_per_process = base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kSitePerProcess);
+  RenderViewHostImpl* render_view_host = nullptr;
+
+  // Ensure a RenderViewHost exists for |instance|, as it creates the page
+  // level structure in Blink.
+  if (is_site_per_process) {
+    render_view_host =
+        frame_tree_node_->frame_tree()->GetRenderViewHost(instance);
+    if (!render_view_host) {
+      CHECK(frame_tree_node_->IsMainFrame());
+      render_view_host = frame_tree_node_->frame_tree()->CreateRenderViewHost(
+          instance, MSG_ROUTING_NONE, MSG_ROUTING_NONE, true, true);
+    }
+  }
+
   RenderFrameProxyHost* proxy = GetRenderFrameProxyHost(instance);
   if (proxy && proxy->is_render_frame_proxy_live())
     return proxy->GetRoutingID();
 
   if (!proxy) {
     proxy = new RenderFrameProxyHost(
-        instance, frame_tree_node_->frame_tree()->GetRenderViewHost(instance),
-        frame_tree_node_);
+        instance, render_view_host, frame_tree_node_);
     proxy_hosts_[instance->GetId()] = proxy;
   }
-  proxy->InitRenderFrameProxy();
+
+  if (is_site_per_process && frame_tree_node_->IsMainFrame()) {
+    InitRenderView(
+        render_view_host, MSG_ROUTING_NONE, proxy->GetRoutingID(), true);
+    proxy->set_render_frame_proxy_created(true);
+  } else {
+    proxy->InitRenderFrameProxy();
+  }
+
   return proxy->GetRoutingID();
 }
 
 void RenderFrameHostManager::CreateProxiesForChildFrame(FrameTreeNode* child) {
   for (const auto& pair : proxy_hosts_) {
     child->render_manager()->CreateRenderFrameProxy(
         pair.second->GetSiteInstance());
   }
 }
 
@@ skipping 13 matching lines @@
   InitRenderView(render_view_host, opener_route_id, proxy->GetRoutingID(),
                  source->IsMainFrame());
   proxy->set_render_frame_proxy_created(true);
 }
 
 bool RenderFrameHostManager::InitRenderView(
     RenderViewHostImpl* render_view_host,
     int opener_route_id,
     int proxy_routing_id,
     bool for_main_frame_navigation) {
-  // We may have initialized this RenderViewHost for another RenderFrameHost.
-  if (render_view_host->IsRenderViewLive())
-    return true;
-
   // Ensure the renderer process is initialized before creating the
   // RenderView.
   if (!render_view_host->GetProcess()->Init())
     return false;
 
+  // We may have initialized this RenderViewHost for another RenderFrameHost.
+  if (render_view_host->IsRenderViewLive())
+    return true;
+
   // If the ongoing navigation is to a WebUI and the RenderView is not in a
   // guest process, tell the RenderViewHost about any bindings it will need
   // enabled.
   WebUIImpl* dest_web_ui = nullptr;
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableBrowserSideNavigation)) {
     dest_web_ui =
         should_reuse_web_ui_ ? web_ui_.get() : speculative_web_ui_.get();
   } else {
     dest_web_ui = pending_web_ui();
   }
   if (dest_web_ui && !render_view_host->GetProcess()->IsIsolatedGuest()) {
     render_view_host->AllowBindings(dest_web_ui->GetBindings());
   } else {
     // Ensure that we don't create an unprivileged RenderView in a WebUI-enabled
     // process unless it's swapped out.
     if (render_view_host->is_active()) {
       CHECK(!ChildProcessSecurityPolicyImpl::GetInstance()->HasWebUIBindings(
                 render_view_host->GetProcess()->GetID()));
     }
   }
 
-  return delegate_->CreateRenderViewForRenderManager(render_view_host,
-                                                     opener_route_id,
-                                                     proxy_routing_id,
-                                                     for_main_frame_navigation);
+  return delegate_->CreateRenderViewForRenderManager(
+      render_view_host,
+      opener_route_id,
+      proxy_routing_id,
+      frame_tree_node_->current_replication_state(),
+      for_main_frame_navigation);
 }
 
 bool RenderFrameHostManager::InitRenderFrame(
     RenderFrameHostImpl* render_frame_host) {
   if (render_frame_host->IsRenderFrameLive())
     return true;
 
   int parent_routing_id = MSG_ROUTING_NONE;
   int previous_sibling_routing_id = MSG_ROUTING_NONE;
   int proxy_routing_id = MSG_ROUTING_NONE;
@@ skipping 49 matching lines @@
 
   return MSG_ROUTING_NONE;
 }
 
 void RenderFrameHostManager::CommitPending() {
   TRACE_EVENT1("navigation", "RenderFrameHostManager::CommitPending",
                "FrameTreeNode id", frame_tree_node_->frame_tree_node_id());
   bool browser_side_navigation =
       base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableBrowserSideNavigation);
+  bool is_site_per_process = base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kSitePerProcess);
+
   // First check whether we're going to want to focus the location bar after
   // this commit.  We do this now because the navigation hasn't formally
   // committed yet, so if we've already cleared |pending_web_ui_| the call chain
   // this triggers won't be able to figure out what's going on.
   bool will_focus_location_bar = delegate_->FocusLocationBarByDefault();
 
   // Next commit the Web UI, if any. Either replace |web_ui_| with
   // |pending_web_ui_|, or clear |web_ui_| if there is no pending WebUI, or
   // leave |web_ui_| as is if reusing it.
   DCHECK(!(pending_web_ui_ && pending_and_current_web_ui_));
@@ skipping 81 matching lines @@
     delegate_->SetFocusToLocationBar(false);
   } else if (focus_render_view && render_frame_host_->GetView()) {
     render_frame_host_->GetView()->Focus();
   }
 
   // Notify that we've swapped RenderFrameHosts. We do this before shutting down
   // the RFH so that we can clean up RendererResources related to the RFH first.
   delegate_->NotifySwappedFromRenderManager(
       old_render_frame_host.get(), render_frame_host_.get(), is_main_frame);
 
+  // The RenderViewHost keeps track of the main RenderFrameHost routing id.
+  // If this is committing a main frame navigation, update it and set the
+  // routing id in the RenderViewHost associated with the old RenderFrameHost
+  // to MSG_ROUTING_NONE.
+  if (is_main_frame && is_site_per_process) {
+    render_frame_host_->render_view_host()->set_main_frame_routing_id(
+        render_frame_host_->routing_id());
+    old_render_frame_host->render_view_host()->set_main_frame_routing_id(
+        MSG_ROUTING_NONE);
+  }
+
   // Swap out the old frame now that the new one is visible.
   // This will swap it out and then put it on the proxy list (if there are other
   // active views in its SiteInstance) or schedule it for deletion when the swap
   // out ack arrives (or immediately if the process isn't live).
   // In the --site-per-process case, old subframe RHFs are not kept alive inside
   // the proxy.
   SwapOutOldFrame(old_render_frame_host.Pass());
 
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kSitePerProcess) &&
-      !is_main_frame) {
+  if (is_site_per_process) {
     // Since the new RenderFrameHost is now committed, there must be no proxies
     // for its SiteInstance. Delete any existing ones.
     RenderFrameProxyHostMap::iterator iter =
         proxy_hosts_.find(render_frame_host_->GetSiteInstance()->GetId());
     if (iter != proxy_hosts_.end()) {
       delete iter->second;
       proxy_hosts_.erase(iter);
     }
 
     // If this is a subframe, it should have a CrossProcessFrameConnector
@@ skipping 281 matching lines @@
 void RenderFrameHostManager::DeleteRenderFrameProxyHost(
     SiteInstance* instance) {
   RenderFrameProxyHostMap::iterator iter = proxy_hosts_.find(instance->GetId());
   if (iter != proxy_hosts_.end()) {
     delete iter->second;
     proxy_hosts_.erase(iter);
   }
 }
 
 }  // namespace content