Implement NavigationThrottle::BLOCK_REQUEST_AND_COLLAPSE.

content/browser/frame_host/frame_tree_node.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/frame_host/frame_tree_node.h"
 
 #include <queue>
 #include <utility>
 
 #include "base/lazy_instance.h"
@@ skipping 88 matching lines @@
                       render_frame_delegate,
                       render_widget_delegate,
                       manager_delegate),
       frame_tree_node_id_(next_frame_tree_node_id_++),
       parent_(parent),
       opener_(nullptr),
       opener_observer_(nullptr),
       original_opener_(nullptr),
       original_opener_observer_(nullptr),
       has_committed_real_load_(false),
+      is_collapsed_by_client_(false),
       replication_state_(
           scope,
           name,
           unique_name,
           blink::WebSandboxFlags::None,
           false /* should enforce strict mixed content checking */,
           false /* is a potentially trustworthy unique origin */,
           false /* has received a user gesture */),
       pending_sandbox_flags_(blink::WebSandboxFlags::None),
       frame_owner_properties_(frame_owner_properties),
@@ skipping 133 matching lines @@
       replication_state_.has_potentially_trustworthy_unique_origin !=
           is_potentially_trustworthy_unique_origin) {
     render_manager_.OnDidUpdateOrigin(origin,
                                       is_potentially_trustworthy_unique_origin);
   }
   replication_state_.origin = origin;
   replication_state_.has_potentially_trustworthy_unique_origin =
       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) {
     // |unique_name| shouldn't change unless |name| changes.
     DCHECK_EQ(unique_name, replication_state_.unique_name);
     return;
   }
 
   if (parent()) {
     // Non-main frames should have a non-empty unique name.
@@ skipping 281 matching lines @@
       }
       return parent_->child_at(i + relative_offset);
     }
   }
 
   NOTREACHED() << "FrameTreeNode not found in its parent's children.";
   return nullptr;
 }
 
 }  // namespace content