Introduce content-side Feature Policy object and maintain in parallel with renderer policy.

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/macros.h"
@@ skipping 240 matching lines @@
   }
 
   RecordUniqueNameLength(unique_name.size());
   render_manager_.OnDidUpdateName(name, unique_name);
   replication_state_.name = name;
   replication_state_.unique_name = unique_name;
 }
 
 void FrameTreeNode::SetFeaturePolicyHeader(
     const ParsedFeaturePolicyHeader& parsed_header) {
+  ResetFeaturePolicy();
   replication_state_.feature_policy_header = parsed_header;
+  feature_policy_->SetHeaderPolicy(parsed_header);
 }
 
 void FrameTreeNode::ResetFeaturePolicy() {
   replication_state_.feature_policy_header.clear();
+  if (parent()) {
+    feature_policy_ = FeaturePolicy::CreateFromParentPolicy(
+        parent()->feature_policy_.get(), current_origin());
+  } else {
+    feature_policy_ =
+        FeaturePolicy::CreateFromParentPolicy(nullptr, current_origin());
+  }

[raymes, 2017/02/01 22:42:20]

optional: alternatively:
FeaturePolicy* parent_policy = parent() ? parent()->feature_policy_.get() :
nullptr;
...

[iclelland, 2017/02/03 16:38:29]

Done.

 }
 
 void FrameTreeNode::AddContentSecurityPolicy(
     const ContentSecurityPolicyHeader& header) {
   replication_state_.accumulated_csp_headers.push_back(header);
   render_manager_.OnDidAddContentSecurityPolicy(header);
 }
 
 void FrameTreeNode::ResetContentSecurityPolicy() {
   replication_state_.accumulated_csp_headers.clear();
@@ skipping 251 matching lines @@
       }
       return parent_->child_at(i + relative_offset);
     }
   }
 
   NOTREACHED() << "FrameTreeNode not found in its parent's children.";
   return nullptr;
 }
 
 }  // namespace content