Implement NavigationThrottle::BLOCK_REQUEST_AND_COLLAPSE.

content/browser/frame_host/frame_tree_node.cc

Index: content/browser/frame_host/frame_tree_node.cc
diff --git a/content/browser/frame_host/frame_tree_node.cc b/content/browser/frame_host/frame_tree_node.cc
index fd58bcb57abcff1bcf72e6c7fe64ae4110f287f2..25d0943f285052b26736441e616ba476424f3199 100644
--- a/content/browser/frame_host/frame_tree_node.cc
+++ b/content/browser/frame_host/frame_tree_node.cc
@@ -106,6 +106,7 @@ FrameTreeNode::FrameTreeNode(FrameTree* frame_tree,
       original_opener_(nullptr),
       original_opener_observer_(nullptr),
       has_committed_real_load_(false),
+      is_collapsed_by_client_(false),
       replication_state_(
           scope,
           name,
@@ -259,6 +260,15 @@ void FrameTreeNode::SetCurrentOrigin(
       is_potentially_trustworthy_unique_origin;
 }
 
+void FrameTreeNode::SetCollapsedByClient(bool collapsed) {
+  DCHECK(!IsMainFrame());
+  if (is_collapsed_by_client_ == collapsed)
+    return;
+
+  is_collapsed_by_client_ = collapsed;
+  render_manager_.OnDidChangeCollapsedByClientState(collapsed);

[nasko, 2017/03/01 20:08:04]

Does the "ByClientState" part of the name add any meaningful distinction? Do we
care at the RFHM layer who initiated the collapsing? Can anyone else do it?

[engedy, 2017/04/10 14:36:41]

I wanted to disambiguate between client- and content-initiated collapsing, but
you are right that it is confusing at this layer. Removed.

+}
+
 void FrameTreeNode::SetFrameName(const std::string& name,
                                  const std::string& unique_name) {
   if (name == replication_state_.name) {