Reliably cancel in-progress CryptoResult(Impl) upon shutdown.

Source/modules/crypto/CryptoResultImpl.cpp

Index: Source/modules/crypto/CryptoResultImpl.cpp
diff --git a/Source/modules/crypto/CryptoResultImpl.cpp b/Source/modules/crypto/CryptoResultImpl.cpp
index 2360727a13a91f34ae1e4352523c2068b1c2c2e2..cdf1f2243020600dc19cac340e29a3f4e627789f 100644
--- a/Source/modules/crypto/CryptoResultImpl.cpp
+++ b/Source/modules/crypto/CryptoResultImpl.cpp
@@ -47,6 +47,7 @@
 #include "modules/crypto/NormalizeAlgorithm.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebCryptoAlgorithm.h"
+#include "wtf/Atomics.h"
 
 namespace blink {
 
@@ -63,7 +64,7 @@ static void rejectWithTypeError(const String& errorDetails, ScriptPromiseResolve
 
 class CryptoResultImpl::Resolver final : public ScriptPromiseResolver {
 public:
-    static PassRefPtrWillBeRawPtr<ScriptPromiseResolver> create(ScriptState* scriptState, CryptoResultImpl* result)
+    static PassRefPtrWillBeRawPtr<Resolver> create(ScriptState* scriptState, CryptoResultImpl* result)
     {
         RefPtrWillBeRawPtr<Resolver> resolver = adoptRefWillBeNoop(new Resolver(scriptState, result));
         resolver->suspendIfNeeded();
@@ -74,18 +75,39 @@ public:
     void stop() override
     {
         m_result->cancel();
-        m_result->clearResolver();
         m_result = nullptr;
         ScriptPromiseResolver::stop();
     }
 
+    DEFINE_INLINE_VIRTUAL_TRACE()
+    {
+        visitor->trace(m_result);
+        ScriptPromiseResolver::trace(visitor);
+    }
+
 private:
     Resolver(ScriptState* scriptState, CryptoResultImpl* result)
         : ScriptPromiseResolver(scriptState)
         , m_result(result) { }
-    RefPtr<CryptoResultImpl> m_result;
+
+    RefPtrWillBeMember<CryptoResultImpl> m_result;
 };
 
+CryptoResultImpl::ResultCancel::ResultCancel()
+    : m_cancelled(0)
+{
+}
+
+bool CryptoResultImpl::ResultCancel::cancelled() const
+{
+    return acquireLoad(&m_cancelled);
+}
+
+void CryptoResultImpl::ResultCancel::cancel()
+{
+    releaseStore(&m_cancelled, 1);
+}
+
 ExceptionCode webCryptoErrorToExceptionCode(WebCryptoErrorType errorType)
 {
     switch (errorType) {
@@ -107,11 +129,31 @@ ExceptionCode webCryptoErrorToExceptionCode(WebCryptoErrorType errorType)
     return 0;
 }
 
+CryptoResultImpl::CryptoResultImpl(ScriptState* scriptState)
+    : m_cancel(ResultCancel::create())
+{
+    ASSERT(scriptState->contextIsValid());
+    if (scriptState->executionContext()->activeDOMObjectsAreStopped()) {
+        // If active dom objects have been stopped, avoid creating
+        // CryptoResultImpl::Resolver.
+        m_resolver = nullptr;
+        m_cancel->cancel();
+        return;
+    }
+    m_resolver = Resolver::create(scriptState, this).get();
+}
+
 CryptoResultImpl::~CryptoResultImpl()
 {
     ASSERT(!m_resolver);
 }
 
+DEFINE_TRACE(CryptoResultImpl)
+{
+    visitor->trace(m_resolver);
+    CryptoResult::trace(visitor);
+}
+
 void CryptoResultImpl::clearResolver()
 {
     m_resolver = nullptr;
@@ -124,96 +166,89 @@ PassRefPtrWillBeRawPtr<CryptoResultImpl> CryptoResultImpl::create(ScriptState* s
 
 void CryptoResultImpl::completeWithError(WebCryptoErrorType errorType, const WebString& errorDetails)
 {
-    if (m_resolver) {
-        ExceptionCode ec = webCryptoErrorToExceptionCode(errorType);
+    if (!m_resolver)
+        return;
 
-        // Handle TypeError separately, as it cannot be created using
-        // DOMException.
-        if (ec == V8TypeError)
-            rejectWithTypeError(errorDetails, m_resolver);
-        else
-            m_resolver->reject(DOMException::create(ec, errorDetails));
-    }
+    ExceptionCode ec = webCryptoErrorToExceptionCode(errorType);
+
+    // Handle TypeError separately, as it cannot be created using
+    // DOMException.
+    if (ec == V8TypeError)
+        rejectWithTypeError(errorDetails, m_resolver);
+    else
+        m_resolver->reject(DOMException::create(ec, errorDetails));
     clearResolver();
 }
 
 void CryptoResultImpl::completeWithBuffer(const void* bytes, unsigned bytesSize)
 {
-    if (m_resolver)
-        m_resolver->resolve(DOMArrayBuffer::create(bytes, bytesSize));
+    if (!m_resolver)
+        return;
+
+    m_resolver->resolve(DOMArrayBuffer::create(bytes, bytesSize));
     clearResolver();
 }
 
 void CryptoResultImpl::completeWithJson(const char* utf8Data, unsigned length)
 {
-    if (m_resolver) {
-        ScriptPromiseResolver* resolver = m_resolver;
-        ScriptState* scriptState = resolver->scriptState();
-        ScriptState::Scope scope(scriptState);
+    if (!m_resolver)
+        return;
 
-        v8::Local<v8::String> jsonString = v8AtomicString(scriptState->isolate(), utf8Data, length);
+    ScriptState* scriptState = m_resolver->scriptState();
+    ScriptState::Scope scope(scriptState);
 
-        v8::TryCatch exceptionCatcher;
-        v8::Local<v8::Value> jsonDictionary;
-        if (v8Call(v8::JSON::Parse(scriptState->isolate(), jsonString), jsonDictionary, exceptionCatcher))
-            resolver->resolve(jsonDictionary);
-        else
-            resolver->reject(exceptionCatcher.Exception());
-    }
+    v8::Local<v8::String> jsonString = v8AtomicString(scriptState->isolate(), utf8Data, length);
+
+    v8::TryCatch exceptionCatcher;
+    v8::Local<v8::Value> jsonDictionary;
+    if (v8Call(v8::JSON::Parse(scriptState->isolate(), jsonString), jsonDictionary, exceptionCatcher))
+        m_resolver->resolve(jsonDictionary);
+    else
+        m_resolver->reject(exceptionCatcher.Exception());
     clearResolver();
 }
 
 void CryptoResultImpl::completeWithBoolean(bool b)
 {
-    if (m_resolver)
-        m_resolver->resolve(b);
+    if (!m_resolver)
+        return;
+
+    m_resolver->resolve(b);
     clearResolver();
 }
 
 void CryptoResultImpl::completeWithKey(const WebCryptoKey& key)
 {
-    if (m_resolver)
-        m_resolver->resolve(CryptoKey::create(key));
+    if (!m_resolver)
+        return;
+
+    m_resolver->resolve(CryptoKey::create(key));
     clearResolver();
 }
 
 void CryptoResultImpl::completeWithKeyPair(const WebCryptoKey& publicKey, const WebCryptoKey& privateKey)
 {
-    if (m_resolver) {
-        ScriptState* scriptState = m_resolver->scriptState();
-        ScriptState::Scope scope(scriptState);
+    if (!m_resolver)
+        return;
 
-        V8ObjectBuilder keyPair(scriptState);
+    ScriptState* scriptState = m_resolver->scriptState();
+    ScriptState::Scope scope(scriptState);
 
-        keyPair.add("publicKey", ScriptValue::from(scriptState, CryptoKey::create(publicKey)));
-        keyPair.add("privateKey", ScriptValue::from(scriptState, CryptoKey::create(privateKey)));
+    V8ObjectBuilder keyPair(scriptState);
 
-        m_resolver->resolve(keyPair.v8Value());
-    }
-    clearResolver();
-}
+    keyPair.add("publicKey", ScriptValue::from(scriptState, CryptoKey::create(publicKey)));
+    keyPair.add("privateKey", ScriptValue::from(scriptState, CryptoKey::create(privateKey)));
 
-bool CryptoResultImpl::cancelled() const
-{
-    return acquireLoad(&m_cancelled);
+    m_resolver->resolve(keyPair.v8Value());
+    clearResolver();
 }
 
 void CryptoResultImpl::cancel()
 {
-    releaseStore(&m_cancelled, 1);
-}
-
-CryptoResultImpl::CryptoResultImpl(ScriptState* scriptState)
-    : m_cancelled(0)
-{
-    ASSERT(scriptState->contextIsValid());
-    if (scriptState->executionContext()->activeDOMObjectsAreStopped()) {
-        // If active dom objects have been stopped, avoid creating
-        // CryptoResultResolver.
-        m_resolver = nullptr;
-    } else {
-        m_resolver = Resolver::create(scriptState, this).get();
-    }
+    ASSERT(m_cancel);
+    m_cancel->cancel();
+    m_cancel.clear();
+    clearResolver();
 }
 
 ScriptPromise CryptoResultImpl::promise()