Resolve FetchEvent.preloadResponse with undefined when Navigation Preload is disabled.

third_party/WebKit/Source/bindings/core/v8/ScriptPromiseProperty.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 ScriptPromiseProperty_h
 #define ScriptPromiseProperty_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromisePropertyBase.h"
 #include "bindings/core/v8/ToV8.h"
@@ skipping 42 matching lines @@
   // ScriptPromiseProperty::Foo to create. The name must be unique
   // per kind of holder.
   template <typename PassHolderType>
   ScriptPromiseProperty(ExecutionContext*, PassHolderType, Name);
 
   ~ScriptPromiseProperty() override {}
 
   template <typename PassResolvedType>
   void resolve(PassResolvedType);
 
+  void resolveWithUndefined();
+
   template <typename PassRejectedType>
   void reject(PassRejectedType);
 
   // Resets this property by unregistering the Promise property from the
   // holder wrapper. Resets the internal state to Pending and clears the
   // resolved and the rejected values.
   // This method keeps the holder object and the property name.
   void reset();
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   v8::Local<v8::Object> holder(v8::Isolate*,
                                v8::Local<v8::Object> creationContext) override;
   v8::Local<v8::Value> resolvedValue(
       v8::Isolate*,
       v8::Local<v8::Object> creationContext) override;
   v8::Local<v8::Value> rejectedValue(
       v8::Isolate*,
       v8::Local<v8::Object> creationContext) override;
 
   HolderType m_holder;
   ResolvedType m_resolved;
   RejectedType m_rejected;
+  bool m_resolvedWithUndefined = false;
 };
 
 template <typename HolderType, typename ResolvedType, typename RejectedType>
 template <typename PassHolderType>
 ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::
     ScriptPromiseProperty(ExecutionContext* executionContext,
                           PassHolderType holder,
                           Name name)
     : ScriptPromisePropertyBase(executionContext, name), m_holder(holder) {}
 
 template <typename HolderType, typename ResolvedType, typename RejectedType>
 template <typename PassResolvedType>
 void ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::resolve(
     PassResolvedType value) {
   if (getState() != Pending) {
-    ASSERT_NOT_REACHED();
+    NOTREACHED();
     return;
   }
   if (!getExecutionContext() || getExecutionContext()->isContextDestroyed())
     return;
   m_resolved = value;
   resolveOrReject(Resolved);
 }
 
 template <typename HolderType, typename ResolvedType, typename RejectedType>
+void ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::
+    resolveWithUndefined() {
+  if (getState() != Pending) {
+    NOTREACHED();
+    return;
+  }
+  if (!getExecutionContext() || getExecutionContext()->isContextDestroyed())
+    return;
+  m_resolvedWithUndefined = true;
+  resolveOrReject(Resolved);
+}
+
+template <typename HolderType, typename ResolvedType, typename RejectedType>
 template <typename PassRejectedType>
 void ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::reject(
     PassRejectedType value) {
   if (getState() != Pending) {
-    ASSERT_NOT_REACHED();
+    NOTREACHED();
     return;
   }
   if (!getExecutionContext() || getExecutionContext()->isContextDestroyed())
     return;
   m_rejected = value;
   resolveOrReject(Rejected);
 }
 
 template <typename HolderType, typename ResolvedType, typename RejectedType>
 v8::Local<v8::Object>
 ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::holder(
     v8::Isolate* isolate,
     v8::Local<v8::Object> creationContext) {
   v8::Local<v8::Value> value = ToV8(m_holder, creationContext, isolate);
   if (value.IsEmpty())
     return v8::Local<v8::Object>();
   return value.As<v8::Object>();
 }
 
 template <typename HolderType, typename ResolvedType, typename RejectedType>
 v8::Local<v8::Value>
 ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::resolvedValue(
     v8::Isolate* isolate,
     v8::Local<v8::Object> creationContext) {
   ASSERT(getState() == Resolved);
-  return ToV8(m_resolved, creationContext, isolate);
+  if (!m_resolvedWithUndefined)
+    return ToV8(m_resolved, creationContext, isolate);
+  return v8::Undefined(isolate);

[haraken, 2017/01/05 07:56:24]

Can we add DCHECK(m_resolved == ResolvedType()) ?

[horo, 2017/01/05 08:13:07]

No we can't.


In file included from
../../third_party/WebKit/Source/modules/encryptedmedia/MediaKeySession.cpp:26:
In file included from
../../third_party/WebKit/Source/modules/encryptedmedia/MediaKeySession.h:30:
../../third_party/WebKit/Source/bindings/core/v8/ScriptPromiseProperty.h:160:21:
error: invalid operands to binary expression ('blink::ToV8UndefinedGenerator'
and 'blink::ToV8UndefinedGenerator')
  DCHECK(m_resolved == ResolvedType());
         ~~~~~~~~~~ ^  ~~~~~~~~~~~~~~

 }
 
 template <typename HolderType, typename ResolvedType, typename RejectedType>
 v8::Local<v8::Value>
 ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::rejectedValue(
     v8::Isolate* isolate,
     v8::Local<v8::Object> creationContext) {
   ASSERT(getState() == Rejected);
   return ToV8(m_rejected, creationContext, isolate);
 }
 
 template <typename HolderType, typename ResolvedType, typename RejectedType>
 void ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::reset() {
   resetBase();
   m_resolved = ResolvedType();
   m_rejected = RejectedType();
+  m_resolvedWithUndefined = false;
 }
 
 template <typename HolderType, typename ResolvedType, typename RejectedType>
 void ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::trace(
     Visitor* visitor) {
   traceImpl(visitor);
 }
 template <typename HolderType, typename ResolvedType, typename RejectedType>
 void ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::trace(
     InlinedGlobalMarkingVisitor visitor) {
   traceImpl(visitor);
 }
 
 template <typename HolderType, typename ResolvedType, typename RejectedType>
 template <typename VisitorDispatcher>
 void ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::traceImpl(
     VisitorDispatcher visitor) {
   TraceIfNeeded<HolderType>::trace(visitor, m_holder);
   TraceIfNeeded<ResolvedType>::trace(visitor, m_resolved);
   TraceIfNeeded<RejectedType>::trace(visitor, m_rejected);
   ScriptPromisePropertyBase::trace(visitor);
 }
 
 }  // namespace blink
 
 #endif  // ScriptPromiseProperty_h