Execute BeforeUnload on subframe browser-initiated 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 ef0e15cfe089cd45d0028deb540f829369f6a4d5..8864d52e038b3889023cf2d31be0e9315956b88d 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -1421,7 +1421,6 @@ void RenderFrameHostImpl::OnBeforeUnloadACK(
   TRACE_EVENT_ASYNC_END1("navigation", "RenderFrameHostImpl BeforeUnload", this,
                          "FrameTreeNode id",
                          frame_tree_node_->frame_tree_node_id());
-  DCHECK(!GetParent());
   // If this renderer navigated while the beforeunload request was in flight, we
   // may have cleared this state in OnDidCommitProvisionalLoad, in which case we
   // can ignore this message.
@@ -2537,8 +2536,9 @@ void RenderFrameHostImpl::SimulateBeforeUnloadAck() {
 }
 
 bool RenderFrameHostImpl::ShouldDispatchBeforeUnload() {
-  // TODO(creis): Support beforeunload on subframes.
-  return !GetParent() && IsRenderFrameLive();
+  // TODO(clamy): Ensure BeforeUnload is dispatched to all subframes, even when
+  // --site-per-process is enabled.

[Charlie Reis, 2017/01/24 21:42:50]

I missed out on the discussion-- what's still left to be done for
--site-per-process?  Maybe we can mention it in the comment.

[clamy, 2017/01/25 14:09:39]

I've moved the comment to a more appropriate place, and explained the issue with
--site-per-process in more details.

+  return IsRenderFrameLive();
 }
 
 void RenderFrameHostImpl::UpdateOpener() {