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

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index 80b1c53831fd626e99defecf41405516c92a4f20..162ed2080ccf73f4672db16266a662a6e40bfe41 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -81,6 +81,7 @@ namespace content {
 class AppWebMessagePortMessageFilter;
 class AssociatedInterfaceProviderImpl;
 class CrossProcessFrameConnector;
+class FeaturePolicy;
 class FrameTree;
 class FrameTreeNode;
 class MediaInterfaceProxy;
@@ -595,6 +596,13 @@ class CONTENT_EXPORT RenderFrameHostImpl
   // in a non-loading state.
   void ResetLoadingState();
 
+  // Returns the feature policy which should be enforced on this RenderFrame.
+  FeaturePolicy* get_feature_policy() { return feature_policy_.get(); }
+
+  // Clears any existing policy and constructs a new policy for this frame,
+  // based on its parent frame.
+  void ResetFeaturePolicy();
+
   // Tells the renderer that this RenderFrame will soon be swapped out, and thus
   // not to create any new modal dialogs until it happens.  This must be done
   // separately so that the ScopedPageLoadDeferrers of any current dialogs are
@@ -1155,6 +1163,9 @@ class CONTENT_EXPORT RenderFrameHostImpl
   // See BindingsPolicy for details.
   int enabled_bindings_ = 0;
 
+  // Tracks the feature policy which has been set on this frame.
+  std::unique_ptr<FeaturePolicy> feature_policy_;
+
   // NOTE: This must be the last member.
   base::WeakPtrFactory<RenderFrameHostImpl> weak_ptr_factory_;