Remove swapped out state from RenderFrameHost.

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index 10615f42110f563377626bbb59613d51d09357ba..ecd65fa80fe3de571b9521792da109c4e4c88527 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -195,6 +195,7 @@ RenderFrameHostImpl::RenderFrameHostImpl(SiteInstance* site_instance,
       frame_tree_node_(frame_tree_node),
       render_widget_host_(nullptr),
       routing_id_(routing_id),
+      rfh_state_(STATE_DEFAULT),
       render_frame_created_(false),
       navigations_suspended_(false),
       is_waiting_for_beforeunload_ack_(false),
@@ -209,7 +210,6 @@ RenderFrameHostImpl::RenderFrameHostImpl(SiteInstance* site_instance,
       pending_web_ui_type_(WebUI::kNoWebUI),
       should_reuse_web_ui_(false),
       weak_ptr_factory_(this) {
-  bool is_swapped_out = !!(flags & CREATE_RF_SWAPPED_OUT);
   bool hidden = !!(flags & CREATE_RF_HIDDEN);
   frame_tree_->AddRenderViewHostRef(render_view_host_);
   GetProcess()->AddRoute(routing_id_, this);
@@ -217,13 +217,7 @@ RenderFrameHostImpl::RenderFrameHostImpl(SiteInstance* site_instance,
       RenderFrameHostID(GetProcess()->GetID(), routing_id_),
       this));
   site_instance_->AddObserver(this);
-
-  if (is_swapped_out) {
-    rfh_state_ = STATE_SWAPPED_OUT;
-  } else {
-    rfh_state_ = STATE_DEFAULT;
-    GetSiteInstance()->IncrementActiveFrameCount();
-  }
+  GetSiteInstance()->IncrementActiveFrameCount();
 
   // New child frames should inherit the nav_entry_id of their parent.
   if (frame_tree_node_->parent()) {
@@ -472,23 +466,6 @@ bool RenderFrameHostImpl::OnMessageReceived(const IPC::Message &msg) {
   if (!render_frame_created_)
     return false;
 
-  // Filter out most IPC messages if this frame is swapped out.

[Charlie Reis, 2016/03/14 20:12:57]

I am so excited about removing this.  :)

[nasko, 2016/03/14 21:32:30]

Same here :).

-  // We still want to handle certain ACKs to keep our state consistent.
-  if (is_swapped_out()) {
-    if (!SwappedOutMessages::CanHandleWhileSwappedOut(msg)) {
-      // If this is a synchronous message and we decided not to handle it,
-      // we must send an error reply, or else the renderer will be stuck
-      // and won't respond to future requests.
-      if (msg.is_sync()) {
-        IPC::Message* reply = IPC::SyncMessage::GenerateReply(&msg);
-        reply->set_reply_error();
-        Send(reply);
-      }
-      // Don't continue looking for someone to handle it.
-      return true;
-    }
-  }
-
   // This message map is for handling internal IPC messages which should not
   // be dispatched to other objects.
   bool handled = true;
@@ -1321,11 +1298,7 @@ void RenderFrameHostImpl::OnRenderProcessGone(int status, int exit_code) {
   // Reset frame tree state associated with this process.  This must happen
   // before RenderViewTerminated because observers expect the subframes of any
   // affected frames to be cleared first.
-  // Note: When a RenderFrameHost is swapped out there is a different one
-  // which is the current host. In this case, the FrameTreeNode state must
-  // not be reset.
-  if (!is_swapped_out())
-    frame_tree_node_->ResetForNewProcess();
+  frame_tree_node_->ResetForNewProcess();
 
   // Reset state for the current RenderFrameHost once the FrameTreeNode has been
   // reset.
@@ -1367,8 +1340,7 @@ void RenderFrameHostImpl::OnSwappedOut() {
     return;
   }
 
-  // If this RFH wasn't pending deletion, then it is now swapped out.
-  SetState(RenderFrameHostImpl::STATE_SWAPPED_OUT);
+  CHECK(false);

[Charlie Reis, 2016/03/14 20:12:57]

Might be clearer if we CHECK the return value of DeleteFromPendingList instead
of having an early return above.

[nasko, 2016/03/14 21:32:30]

Good idea. Done, but keeping a variable around to ensure that the call is made
unconditionally. Being paranoid about what CHECK might do in the future.

 }
 
 void RenderFrameHostImpl::OnContextMenu(const ContextMenuParams& params) {
@@ -1893,33 +1865,24 @@ void RenderFrameHostImpl::RegisterMojoServices() {
 }
 
 void RenderFrameHostImpl::SetState(RenderFrameHostImplState rfh_state) {
-  // Only main frames should be swapped out and retained inside a proxy host.
-  if (rfh_state == STATE_SWAPPED_OUT)
-    CHECK(!GetParent());
-
-  // We update the number of RenderFrameHosts in a SiteInstance when the swapped
-  // out status of a RenderFrameHost gets flipped to/from active.
+  // We update the number of RenderFrameHosts in a SiteInstance when the status
+  // of a RenderFrameHost gets flipped to/from active.

[Charlie Reis, 2016/03/14 20:12:57]

Is it even possible for the state to go from inactive to active now?  Seems like
this can get even simpler.

[nasko, 2016/03/14 21:32:30]

Done.

   if (!IsRFHStateActive(rfh_state_) && IsRFHStateActive(rfh_state))
     GetSiteInstance()->IncrementActiveFrameCount();
   else if (IsRFHStateActive(rfh_state_) && !IsRFHStateActive(rfh_state))
     GetSiteInstance()->DecrementActiveFrameCount();
 
-  // The active and swapped out state of the RVH is determined by its main
-  // frame, since subframes should have their own widgets.
-  if (frame_tree_node_->IsMainFrame()) {
+  // The active state of the RVH is determined by its main frame, since
+  // subframes should have their own widgets.
+  if (frame_tree_node_->IsMainFrame())
     render_view_host_->set_is_active(IsRFHStateActive(rfh_state));
-    render_view_host_->set_is_swapped_out(rfh_state == STATE_SWAPPED_OUT);
-  }
 
-  // Whenever we change the RFH state to and from active or swapped out state,
-  // we should not be waiting for beforeunload or close acks.  We clear them
-  // here to be safe, since they can cause navigations to be ignored in
+  // Whenever we change the RFH state to and from active state, we should not be
+  // waiting for beforeunload or close acks.  We clear them here to be safe,
+  // since they can cause navigations to be ignored in
   // OnDidCommitProvisionalLoad.
   // TODO(creis): Move is_waiting_for_beforeunload_ack_ into the state machine.
-  if (rfh_state == STATE_DEFAULT ||
-      rfh_state == STATE_SWAPPED_OUT ||
-      rfh_state_ == STATE_DEFAULT ||
-      rfh_state_ == STATE_SWAPPED_OUT) {
+  if (rfh_state == STATE_DEFAULT || rfh_state_ == STATE_DEFAULT) {
     if (is_waiting_for_beforeunload_ack_) {
       is_waiting_for_beforeunload_ack_ = false;
       render_view_host_->GetWidget()->decrement_in_flight_event_count();