Feature policy: Add basic algorithm for supporting frame policies.

third_party/WebKit/Source/platform/feature_policy/FeaturePolicy.h

Index: third_party/WebKit/Source/platform/feature_policy/FeaturePolicy.h
diff --git a/third_party/WebKit/Source/platform/feature_policy/FeaturePolicy.h b/third_party/WebKit/Source/platform/feature_policy/FeaturePolicy.h
index f45ccd19961f77e3ec3c1ffe87149911e8663039..9482def2a2f57eddaa211d0f81b1e158b89086d6 100644
--- a/third_party/WebKit/Source/platform/feature_policy/FeaturePolicy.h
+++ b/third_party/WebKit/Source/platform/feature_policy/FeaturePolicy.h
@@ -139,6 +139,7 @@ class PLATFORM_EXPORT FeaturePolicy final {
 
   static std::unique_ptr<FeaturePolicy> createFromParentPolicy(
       const FeaturePolicy* parent,
+      const WebParsedFeaturePolicyHeader* framePolicy,
       RefPtr<SecurityOrigin>);
 
   // Sets the declared policy from the parsed Feature-Policy HTTP header.
@@ -170,9 +171,13 @@ class PLATFORM_EXPORT FeaturePolicy final {
 
   static std::unique_ptr<FeaturePolicy> createFromParentPolicy(
       const FeaturePolicy* parent,
+      const WebParsedFeaturePolicyHeader* framePolicy,
       RefPtr<SecurityOrigin>,
       FeatureList& features);
 
+  void addFramePolicy(const FeaturePolicy* parent,
+                      const WebParsedFeaturePolicyHeader* framePolicy);
+
   RefPtr<SecurityOrigin> m_origin;
 
   // Records whether or not each feature was enabled for this frame by its