Feature policy: Add basic algorithm for supporting frame policies.

content/common/feature_policy/feature_policy.h

Index: content/common/feature_policy/feature_policy.h
diff --git a/content/common/feature_policy/feature_policy.h b/content/common/feature_policy/feature_policy.h
index 44f9e11f2667a5f59dad7b5652fd8e4257ed0511..b470dcf9a0dd397a9c37988ed8880bab40f42eac 100644
--- a/content/common/feature_policy/feature_policy.h
+++ b/content/common/feature_policy/feature_policy.h
@@ -159,6 +159,7 @@ class CONTENT_EXPORT FeaturePolicy {
 
   static std::unique_ptr<FeaturePolicy> CreateFromParentPolicy(
       const FeaturePolicy* parent_policy,
+      const ParsedFeaturePolicyHeader* frame_policy,

[raymes, 2017/02/20 02:20:17]

nit: it's a bit weird that we pass a ParsedFeaturePolicyHeader here. We might
want to consider that at some point though it's a minor issue in the scheme of
things.

I wonder if it's better to name the variable frame_owner_policy or iframe_policy
to be a bit clearer for readers?

[iclelland, 2017/02/21 19:51:05]

I've started using the term 'container policy' in the spec, to avoid overloading
the term 'frame' even further. I'll change it to that here for consistency.

       const url::Origin& origin);
 
   // Returns whether or not the given feature is enabled by this policy.
@@ -180,9 +181,15 @@ class CONTENT_EXPORT FeaturePolicy {
   FeaturePolicy(url::Origin origin, const FeatureList& feature_list);
   static std::unique_ptr<FeaturePolicy> CreateFromParentPolicy(
       const FeaturePolicy* parent_policy,
+      const ParsedFeaturePolicyHeader* frame_policy,
       const url::Origin& origin,
       const FeatureList& features);
 
+  // Updates the inherited policy with the declarations from the iframe allow*
+  // attributes.
+  void AddFramePolicy(const FeaturePolicy* parent_policy,
+                      const ParsedFeaturePolicyHeader* frame_policy);
+
   // Returns the list of features which can be controlled by Feature Policy.
   static const FeatureList& GetDefaultFeatureList();