Part 3.5: Is policy list subsumed under subsuming policy?

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

Index: third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.cpp
diff --git a/third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.cpp b/third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.cpp
index eef9c62fb00e3d4e9e96e65f3443fd979bbb851b..5b5625d989815bc9656598884106cff7f92cf53f 100644
--- a/third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.cpp
+++ b/third_party/WebKit/Source/core/frame/csp/CSPDirectiveList.cpp
@@ -1216,8 +1216,11 @@ SourceListDirectiveVector CSPDirectiveList::getSourceVector(
     const CSPDirectiveListVector& policies) {
   SourceListDirectiveVector sourceListDirectives;
   for (const auto& policy : policies) {
-    if (SourceListDirective* directive = policy->operativeDirective(type))
+    if (SourceListDirective* directive = policy->operativeDirective(type)) {
+      if (directive->isNone())
+        return SourceListDirectiveVector(1, directive);
       sourceListDirectives.append(directive);
+    }
   }
 
   return sourceListDirectives;
@@ -1248,7 +1251,7 @@ bool CSPDirectiveList::subsumes(const CSPDirectiveListVector& other) {
     // Embedding-CSP.
     SourceListDirectiveVector requiredList =
         getSourceVector(directive, CSPDirectiveListVector(1, this));
-    if (requiredList.size() == 0)
+    if (!requiredList.size())
       continue;
     SourceListDirective* required = requiredList[0];
     // Aggregate all serialized source lists of the returned CSP into a vector