Allow RenderFrames to swap out for subframe navigations.

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 620d87dc08004cbd4e42842132f61186c9543e5b..a01344fd8102884498c9478c458e74a03e87dd8c 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -115,6 +115,7 @@ bool RenderFrameHostImpl::OnMessageReceived(const IPC::Message &msg) {
     IPC_MESSAGE_HANDLER(FrameHostMsg_Detach, OnDetach)
     IPC_MESSAGE_HANDLER(FrameHostMsg_DidStartProvisionalLoadForFrame,
                         OnDidStartProvisionalLoadForFrame)
+    IPC_MESSAGE_HANDLER(FrameHostMsg_SwapOut_ACK, OnSwapOutACK)
   IPC_END_MESSAGE_MAP_EX()
 
   if (!msg_is_ok) {
@@ -154,4 +155,22 @@ void RenderFrameHostImpl::OnDidStartProvisionalLoadForFrame(
       this, frame_id, parent_frame_id, is_main_frame, url);
 }
 
+void RenderFrameHostImpl::SwapOut() {
+  if (render_view_host_->IsRenderViewLive()) {
+    Send(new FrameMsg_SwapOut(routing_id()));
+  } else {
+    // Our RenderViewHost doesn't have a live renderer, so just skip the unload
+    // event.
+    OnSwappedOut(true);
+  }
+}
+
+void RenderFrameHostImpl::OnSwapOutACK() {
+  OnSwappedOut(false);
+}
+
+void RenderFrameHostImpl::OnSwappedOut(bool timed_out) {
+  frame_tree_node_->render_manager()->SwappedOutFrame(this);
+}
+
 }  // namespace content