[WIP NOT FOR COMMIT] Feature policy: Add basic algorithm for supporting frame policies, start plumb…

content/common/feature_policy/feature_policy.cc

Index: content/common/feature_policy/feature_policy.cc
diff --git a/content/common/feature_policy/feature_policy.cc b/content/common/feature_policy/feature_policy.cc
index b51bee50b30949fab7dc872c4fdb26d5df6b11ca..7d529bdc206d850ddf1362b911d898ba7a82c07c 100644
--- a/content/common/feature_policy/feature_policy.cc
+++ b/content/common/feature_policy/feature_policy.cc
@@ -107,8 +107,10 @@ bool FeaturePolicy::Whitelist::Contains(const url::Origin& origin) const {
 // static
 std::unique_ptr<FeaturePolicy> FeaturePolicy::CreateFromParentPolicy(
     const FeaturePolicy* parent_policy,
+    const FeaturePolicyHeader* frame_policy,
     url::Origin origin) {
-  return CreateFromParentPolicy(parent_policy, origin, getDefaultFeatureList());
+  return CreateFromParentPolicy(parent_policy, frame_policy, origin,
+                                getDefaultFeatureList());
 }
 
 bool FeaturePolicy::IsFeatureEnabledForOrigin(
@@ -159,8 +161,14 @@ FeaturePolicy::FeaturePolicy(url::Origin origin)
 FeaturePolicy::~FeaturePolicy() {}
 
 // static
+/*
+ * To Add to this: another FeaturePolicyHeader for irame attributes.
+ * In that case, we change the inherited polies, but only if the parent allows
+ * it for itself (or we check the parent inherited policy; see which is better)
+ */
 std::unique_ptr<FeaturePolicy> FeaturePolicy::CreateFromParentPolicy(
     const FeaturePolicy* parent_policy,
+    const FeaturePolicyHeader* frame_policy,
     url::Origin origin,
     const FeaturePolicy::FeatureList& features) {
   std::unique_ptr<FeaturePolicy> newPolicy =
@@ -172,10 +180,34 @@ std::unique_ptr<FeaturePolicy> FeaturePolicy::CreateFromParentPolicy(
     } else {
       newPolicy->inherited_policies_[feature.first] = false;
     }
+    if (frame_policy) {
+      newPolicy->AddFramePolicy(parent_policy, frame_policy);
+    }
   }
   return newPolicy;
 }
 
+void FeaturePolicy::AddFramePolicy(const FeaturePolicy* parent_policy,
+                                   const FeaturePolicyHeader* frame_policy) {
+  DCHECK(parent_policy);
+  DCHECK(frame_policy);
+  for (const FeaturePolicyParsedDeclaration& parsed_declaration :
+       *frame_policy) {
+    blink::WebFeaturePolicyFeature feature =
+        FeatureForName(parsed_declaration.feature_name, feature_list_);
+    if (feature == blink::WebFeaturePolicyFeature::NotFound)
+      continue;
+    if (WhitelistFromDeclaration(parsed_declaration)->Contains(origin_) &&
+        // TODO: Check to see if this should look at
+        // parent_policy->inherited_policies_ instead.
+        parent_policy->IsFeatureEnabled(feature)) {
+      inherited_policies_[feature] = true;
+    } else {
+      inherited_policies_[feature] = false;
+    }
+  }
+}
+
 // static
 const FeaturePolicy::FeatureList& FeaturePolicy::getDefaultFeatureList() {
   // TODO: See if this should use lazy_instance instead