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

Source/platform/exported/WebCryptoResult.cpp

Index: Source/platform/exported/WebCryptoResult.cpp
diff --git a/Source/platform/exported/WebCryptoResult.cpp b/Source/platform/exported/WebCryptoResult.cpp
index d5515064a86e9aa829d129b2828f678f1820fadf..a01b3bd02f233de76c0884060011cd8d980a97d6 100644
--- a/Source/platform/exported/WebCryptoResult.cpp
+++ b/Source/platform/exported/WebCryptoResult.cpp
@@ -33,58 +33,72 @@
 
 #include "platform/CryptoResult.h"
 #include "platform/heap/Heap.h"
-#include <string.h>
+#include "wtf/Atomics.h"
 
 namespace blink {
 
 void WebCryptoResult::completeWithError(WebCryptoErrorType errorType, const WebString& errorDetails)
 {
+    if (cancelled())
+        return;
     m_impl->completeWithError(errorType, errorDetails);
-    reset();
+    clear();
 }
 
 void WebCryptoResult::completeWithBuffer(const void* bytes, unsigned bytesSize)
 {
+    if (cancelled())
+        return;
     m_impl->completeWithBuffer(bytes, bytesSize);
-    reset();
+    clear();
 }
 
 void WebCryptoResult::completeWithJson(const char* utf8Data, unsigned length)
 {
+    if (cancelled())
+        return;
     m_impl->completeWithJson(utf8Data, length);
-    reset();
+    clear();
 }
 
 void WebCryptoResult::completeWithBoolean(bool b)
 {
+    if (cancelled())
+        return;
     m_impl->completeWithBoolean(b);
-    reset();
+    clear();
 }
 
 void WebCryptoResult::completeWithKey(const WebCryptoKey& key)
 {
+    if (cancelled())
+        return;
     ASSERT(!key.isNull());
     m_impl->completeWithKey(key);
-    reset();
+    clear();
 }
 
 void WebCryptoResult::completeWithKeyPair(const WebCryptoKey& publicKey, const WebCryptoKey& privateKey)
 {
+    if (cancelled())
+        return;
     ASSERT(!publicKey.isNull());
     ASSERT(!privateKey.isNull());
     m_impl->completeWithKeyPair(publicKey, privateKey);
-    reset();
+    clear();
 }
 
 bool WebCryptoResult::cancelled() const
 {
-    return m_impl->cancelled();
+    return acquireLoad(&m_cancelled);
 }
 
 WebCryptoResult::WebCryptoResult(const PassRefPtrWillBeRawPtr<CryptoResult>& impl)
-    : m_impl(impl)
+    : m_cancelled(0)
+    , m_impl(impl)
 {
     ASSERT(m_impl.get());
+    m_impl->assignedTo(this);
 }
 
 void WebCryptoResult::reset()
@@ -92,9 +106,22 @@ void WebCryptoResult::reset()
     m_impl.reset();
 }
 
+void WebCryptoResult::clear()
+{
+    if (!m_impl.isNull()) {
+        releaseStore(&m_cancelled, 1);
+        m_impl->assignedTo(nullptr);
+    }
+    reset();
+}
+
 void WebCryptoResult::assign(const WebCryptoResult& o)
 {
+    ASSERT(!o.m_cancelled);
+    ASSERT(!o.m_impl.isNull());
+    m_cancelled = o.m_cancelled;
     m_impl = o.m_impl;
+    m_impl->assignedTo(this);
 }
 
 } // namespace blink