[Experimental Framework] Make the OriginTrialContext a member of ExecutionContext

third_party/WebKit/Source/core/dom/ExecutionContext.h

 /*
  * 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 35 matching lines @@
 namespace blink {
 
 class ActiveDOMObject;
 class ConsoleMessage;
 class DOMTimerCoordinator;
 class ErrorEvent;
 class EventQueue;
 class EventTarget;
 class ExecutionContextTask;
 class LocalDOMWindow;
+class OriginTrials;
+class OriginTrialContext;
 class PublicURLManager;
 class SecurityOrigin;
 class ScriptCallStack;
 
 class CORE_EXPORT ExecutionContext
     : public ContextLifecycleNotifier, public WillBeHeapSupplementable<ExecutionContext> {
     WTF_MAKE_NONCOPYABLE(ExecutionContext);
 public:
     DECLARE_VIRTUAL_TRACE();
 
     // Used to specify whether |isSecureContext| should walk the
     // ancestor tree to decide whether to restrict usage of a powerful
     // feature.
     enum SecureContextCheck {
         StandardSecureContextCheck,
         WebCryptoSecureContextCheck
     };
 
     virtual bool isDocument() const { return false; }
     virtual bool isWorkerGlobalScope() const { return false; }
     virtual bool isWorkletGlobalScope() const { return false; }
     virtual bool isDedicatedWorkerGlobalScope() const { return false; }
     virtual bool isSharedWorkerGlobalScope() const { return false; }
     virtual bool isServiceWorkerGlobalScope() const { return false; }
     virtual bool isCompositorWorkerGlobalScope() const { return false; }
     virtual bool isJSExecutionForbidden() const { return false; }
 
     virtual bool isContextThread() const { return true; }
 
+    OriginTrials* originTrials();
     SecurityOrigin* securityOrigin();
     ContentSecurityPolicy* contentSecurityPolicy();
     const KURL& url() const;
     KURL completeURL(const String& url) const;
     virtual void disableEval(const String& errorMessage) = 0;
     virtual LocalDOMWindow* executingWindow() { return 0; }
     virtual String userAgent() const = 0;
     virtual void postTask(const WebTraceLocation&, PassOwnPtr<ExecutionContextTask>) = 0; // Executes the task on context's thread asynchronously.
 
     // Gets the DOMTimerCoordinator which maintains the "active timer
@@ skipping 68 matching lines @@
     ExecutionContext();
     virtual ~ExecutionContext();
 
     virtual const KURL& virtualURL() const = 0;
     virtual KURL virtualCompleteURL(const String&) const = 0;
 
 private:
     bool dispatchErrorEvent(PassRefPtrWillBeRawPtr<ErrorEvent>, AccessControlStatus);
     void runSuspendableTasks();
 
+    // Override to enable experimental features through origin trials
+    virtual OriginTrialContext* originTrialContext() { return nullptr; }
+
 #if !ENABLE(OILPAN)
     virtual void refExecutionContext() = 0;
     virtual void derefExecutionContext() = 0;
 #endif
     // LifecycleContext implementation.
 
     unsigned m_circularSequentialID;
 
     bool m_inDispatchErrorEvent;
     class PendingException;
     OwnPtr<Vector<OwnPtr<PendingException>>> m_pendingExceptions;
 
     bool m_activeDOMObjectsAreSuspended;
     bool m_activeDOMObjectsAreStopped;
 
     OwnPtrWillBeMember<PublicURLManager> m_publicURLManager;
 
     // Counter that keeps track of how many window interaction calls are allowed
     // for this ExecutionContext. Callers are expected to call
     // |allowWindowInteraction()| and |consumeWindowInteraction()| in order to
     // increment and decrement the counter.
     int m_windowInteractionTokens;
 
     Deque<OwnPtr<SuspendableTask>> m_suspendedTasks;
     bool m_isRunSuspendableTasksScheduled;
 
     ReferrerPolicy m_referrerPolicy;
+
+    // Experimental framework policy and cache
+    OwnPtr<OriginTrials> m_originTrials;

[jbroman, 2016/03/01 23:29:21]

One thought here: consider using a supplement
(WillBeHeapSupplement<ExecutionContext>, see platform/Supplementable.h) instead
of adding a field to every execution context, especially since this is likely to
be rare (at least until developers start using the origin trials feature).
ExecutionContext is already supplementable.

I'd prefer to keep the number of feature-specific fields in ExecutionContext low
if possible.

[iclelland, 2016/03/03 21:47:01]

That's a really good idea. Thanks, done.

 };
 
 } // namespace blink
 
 #endif // ExecutionContext_h