Dispatch unload event for swapped-out subframes.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index e1255bcb9e18bed22dca2c2eaa1ab4ba914e0f19..93c58f5fdd111ae8a60a6ed921482cc86d0eb5a5 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -1790,12 +1790,6 @@ void RenderFrameImpl::OnSwapOut(
   proxy = RenderFrameProxy::CreateProxyToReplaceFrame(
       this, proxy_routing_id, replicated_frame_state.scope);
 
-  // Synchronously run the unload handler before sending the ACK.
-  // TODO(creis): Call dispatchUnloadEvent unconditionally here to support
-  // unload on subframes as well.
-  if (is_main_frame_)
-    frame_->DispatchUnloadEvent();
-
   // Swap out and stop sending any IPC messages that are not ACKs.
   if (is_main_frame_)
     render_view_->SetSwappedOut(true);