Enforce referrer policies for workers

Source/core/dom/ExecutionContext.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2012 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 14 matching lines @@
  *
  */
 
 #include "config.h"
 #include "core/dom/ExecutionContext.h"
 
 #include "core/dom/ExecutionContextTask.h"
 #include "core/events/ErrorEvent.h"
 #include "core/events/EventTarget.h"
 #include "core/fetch/MemoryCache.h"
+#include "core/frame/UseCounter.h"
 #include "core/html/PublicURLManager.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/inspector/ScriptCallStack.h"
 #include "core/workers/WorkerGlobalScope.h"
 #include "core/workers/WorkerThread.h"
 #include "wtf/MainThread.h"
 
 namespace blink {
 
 class ExecutionContext::PendingException : public NoBaseWillBeGarbageCollectedFinalized<ExecutionContext::PendingException> {
@@ skipping 21 matching lines @@
 };
 
 ExecutionContext::ExecutionContext()
     : m_circularSequentialID(0)
     , m_inDispatchErrorEvent(false)
     , m_activeDOMObjectsAreSuspended(false)
     , m_activeDOMObjectsAreStopped(false)
     , m_strictMixedContentCheckingEnforced(false)
     , m_windowInteractionTokens(0)
     , m_isRunSuspendableTasksScheduled(false)
+    , m_referrerPolicy(ReferrerPolicyDefault)
 {
 }
 
 ExecutionContext::~ExecutionContext()
 {
 }
 
 void ExecutionContext::suspendActiveDOMObjects()
 {
     ASSERT(!m_activeDOMObjectsAreSuspended);
@@ skipping 155 matching lines @@
     if (m_windowInteractionTokens == 0)
         return;
     --m_windowInteractionTokens;
 }
 
 bool ExecutionContext::isWindowInteractionAllowed() const
 {
     return m_windowInteractionTokens > 0;
 }
 
+void ExecutionContext::setReferrerPolicy(ReferrerPolicy referrerPolicy)
+{
+    // FIXME: Can we adopt the CSP referrer policy merge algorithm? Or does the web rely on being able to modify the referrer policy in-flight?
+    UseCounter::count(this, UseCounter::SetReferrerPolicy);
+    if (m_referrerPolicy != ReferrerPolicyDefault)

[jochen (gone - plz use gerrit), 2015/05/04 07:20:31]

i notice this is just copy/paste, but shouldn't this be == ?

[Mike West, 2015/05/04 14:17:20]

I don't think so. If the referrer policy is the default policy (as opposed to
`ReferrerPolicyNoReferrerWhenDowngrade`), then no policy has been set. If a
policy has been set, it will be something other than "default", so we log a
reset.

Also, I think we have enough data here showing that resets are common to simply
throw away the merge algorithm in the spec and define one that matches the web.

[jochen (gone - plz use gerrit), 2015/05/04 14:36:12]

ah, right

+        UseCounter::count(this, UseCounter::ResetReferrerPolicy);
+
+    m_referrerPolicy = referrerPolicy;
+}
+
 void ExecutionContext::removeURLFromMemoryCache(const KURL& url)
 {
     memoryCache()->removeURLFromCache(url);
 }
 
 DEFINE_TRACE(ExecutionContext)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_pendingExceptions);
     visitor->trace(m_publicURLManager);
     HeapSupplementable<ExecutionContext>::trace(visitor);
 #endif
     ContextLifecycleNotifier::trace(visitor);
 }
 
 } // namespace blink