Part 3.1: Is policy list subsumed under subsuming policy?

third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.h

Index: third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.h
diff --git a/third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.h b/third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.h
index 51ab571882a0465373623897c3833e542941dbc1..e9aeef2a87b294cdfed4de3e8240cb90dfa142ce 100644
--- a/third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.h
+++ b/third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.h
@@ -22,6 +22,8 @@ namespace blink {
 
 class ContentSecurityPolicy;
 
+typedef HeapVector<Member<SourceListDirective>> SourceListDirectiveVector;
+
 class CORE_EXPORT CSPDirectiveList
     : public GarbageCollectedFinalized<CSPDirectiveList> {
   WTF_MAKE_NONCOPYABLE(CSPDirectiveList);
@@ -156,10 +158,15 @@ class CORE_EXPORT CSPDirectiveList
 
   bool shouldSendCSPHeader(Resource::Type) const;
 
+  // The algorithm is described here:
+  // https://w3c.github.io/webappsec-csp/embedded/#subsume-policy
+  bool subsumes(CSPDirectiveListVector);
+
   DECLARE_TRACE();
 
  private:
   FRIEND_TEST_ALL_PREFIXES(CSPDirectiveListTest, IsMatchingNoncePresent);
+  FRIEND_TEST_ALL_PREFIXES(CSPDirectiveListTest, GetSourceVector);
 
   enum RequireSRIForToken { None = 0, Script = 1 << 0, Style = 1 << 1 };
 
@@ -266,6 +273,12 @@ class CORE_EXPORT CSPDirectiveList
 
   bool denyIfEnforcingPolicy() const { return isReportOnly(); }
 
+  SourceListDirective* operativeDirective(

[Mike West, 2016/11/24 13:07:46]

Please add unit tests, especially for the cascade behavior.

[amalika, 2016/11/24 14:32:29]

Added!

+      const ContentSecurityPolicy::DirectiveType&);
+  static SourceListDirectiveVector getSourceVector(

[Mike West, 2016/11/24 13:07:46]

Can you add a comment explaining what these functions do?

[amalika, 2016/11/24 14:32:29]

Added!

+      const ContentSecurityPolicy::DirectiveType&,
+      CSPDirectiveListVector policies);
+
   Member<ContentSecurityPolicy> m_policy;
 
   String m_header;