Part 2.3: Is policy list subsumed under subsuming policy?

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/frame/csp/CSPSource.h"
 
 #include "core/frame/UseCounter.h"
 #include "core/frame/csp/ContentSecurityPolicy.h"
 #include "platform/weborigin/KURL.h"
 #include "platform/weborigin/KnownPorts.h"
@@ skipping 127 matching lines @@
     return true;
 
   return false;
 }
 
 CSPSource* CSPSource::intersect(CSPSource* other) {
   if (!isSimilar(other))
     return nullptr;
 
   String scheme = other->schemeMatches(m_scheme) ? m_scheme : other->m_scheme;
+  if (isSchemeOnly() || other->isSchemeOnly()) {

[Mike West, 2016/11/17 10:58:31]

Unit test?

[amalika, 2016/11/19 18:34:32]

Added `IntersectSchemesOnly`!
(and test `Intersect` just in case)

+    CSPSource* stricter = isSchemeOnly() ? other : this;
+    return new CSPSource(m_policy, scheme, stricter->m_host, stricter->m_port,
+                         stricter->m_path, stricter->m_hostWildcard,
+                         stricter->m_portWildcard);
+  }
+
   String host = m_hostWildcard == NoWildcard ? m_host : other->m_host;
   String path = other->pathMatches(m_path) ? m_path : other->m_path;
   int port = (other->m_portWildcard == HasWildcard || !other->m_port)
                  ? m_port
                  : other->m_port;
   WildcardDisposition hostWildcard =
       (m_hostWildcard == HasWildcard) ? other->m_hostWildcard : m_hostWildcard;
   WildcardDisposition portWildcard =
       (m_portWildcard == HasWildcard) ? other->m_portWildcard : m_portWildcard;
   return new CSPSource(m_policy, scheme, host, port, path, hostWildcard,
                        portWildcard);
 }
 
 bool CSPSource::isSchemeOnly() const {
   return m_host.isEmpty();
 }
 
 DEFINE_TRACE(CSPSource) {
   visitor->trace(m_policy);
 }
 
 }  // namespace blink