Add ScriptPromiseResolver::detach

third_party/WebKit/Source/bindings/core/v8/ScriptPromiseResolver.h

 // 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.
 
 #ifndef ScriptPromiseResolver_h
 #define ScriptPromiseResolver_h
 
 #include "bindings/core/v8/ScopedPersistent.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptState.h"
@@ skipping 28 matching lines @@
 
 #if ENABLE(ASSERT)
     // Eagerly finalized so as to ensure valid access to executionContext()
     // from the destructor's assert.
     EAGERLY_FINALIZE();
 
     ~ScriptPromiseResolver() override
     {
         // This assertion fails if:
         //  - promise() is called at least once and
-        //  - this resolver is destructed before it is resolved, rejected, the
-        //    V8 isolate is terminated or the associated ExecutionContext is
-        //    stopped.
-        ASSERT(m_state == ResolvedOrRejected || !m_isPromiseCalled || !scriptState()->contextIsValid() || !executionContext() || executionContext()->activeDOMObjectsAreStopped());
+        //  - this resolver is destructed before it is resolved, rejected,
+        //    detached, the V8 isolate is terminated or the associated
+        //    ExecutionContext is stopped.
+        ASSERT(m_state == Detached || !m_isPromiseCalled || !scriptState()->contextIsValid() || !executionContext() || executionContext()->activeDOMObjectsAreStopped());
     }
 #endif
 
     // Anything that can be passed to toV8 can be passed to this function.
     template<typename T>
     void resolve(T value)
     {
         resolveOrReject(value, Resolving);
     }
 
@@ skipping 17 matching lines @@
         m_isPromiseCalled = true;
 #endif
         return m_resolver.promise();
     }
 
     ScriptState* scriptState() const { return m_scriptState.get(); }
 
     // ActiveDOMObject implementation.
     void suspend() override;
     void resume() override;
-    void stop() override;
+    void stop() override { detach(); }
+
+    // Calling this function makes the resolver release its internal resources.
+    // That means the associated promise will never be resolved or rejected
+    // unless it's already been resolved or rejected.
+    // Do not call this function unless you truly need the behavior.
+    void detach();
 
     // Once this function is called this resolver stays alive while the
     // promise is pending and the associated ExecutionContext isn't stopped.
     void keepAliveWhilePending();
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     // You need to call suspendIfNeeded after the construction because
     // this is an ActiveDOMObject.
     explicit ScriptPromiseResolver(ScriptState*);
 
 private:
     typedef ScriptPromise::InternalResolver Resolver;
     enum ResolutionState {
         Pending,
         Resolving,
         Rejecting,
-        ResolvedOrRejected,
+        Detached,
     };
 
     template<typename T>
     void resolveOrReject(T value, ResolutionState newState)
     {
         if (m_state != Pending || !scriptState()->contextIsValid() || !executionContext() || executionContext()->activeDOMObjectsAreStopped())
             return;
         ASSERT(newState == Resolving || newState == Rejecting);
         m_state = newState;
 
         ScriptState::Scope scope(m_scriptState.get());
         m_value.set(
             m_scriptState->isolate(),
             toV8(value, m_scriptState->context()->Global(), m_scriptState->isolate()));
 
         if (executionContext()->activeDOMObjectsAreSuspended()) {
             // Retain this object until it is actually resolved or rejected.
             keepAliveWhilePending();
             return;
         }
         resolveOrRejectImmediately();
     }
 
     void resolveOrRejectImmediately();
     void onTimerFired(Timer<ScriptPromiseResolver>*);
-    void clear();
 
     ResolutionState m_state;
     const RefPtr<ScriptState> m_scriptState;
     Timer<ScriptPromiseResolver> m_timer;
     Resolver m_resolver;
     ScopedPersistent<v8::Value> m_value;
 
     // To support keepAliveWhilePending(), this object needs to keep itself
     // alive while in that state.
     SelfKeepAlive<ScriptPromiseResolver> m_keepAlive;
 
 #if ENABLE(ASSERT)
     // True if promise() is called.
     bool m_isPromiseCalled;
 #endif
 };
 
 } // namespace blink
 
 #endif // ScriptPromiseResolver_h