WebCrypto: Add the KeyPair interface.

Source/modules/crypto/CryptoResult.cpp

Index: Source/modules/crypto/CryptoResult.cpp
diff --git a/Source/modules/crypto/CryptoResult.cpp b/Source/modules/crypto/CryptoResult.cpp
index d2885527dc1e733361917d1427cb9569d9e01fed..ee89a79c6e4a563d7cb4e557162631f8853e3d64 100644
--- a/Source/modules/crypto/CryptoResult.cpp
+++ b/Source/modules/crypto/CryptoResult.cpp
@@ -32,6 +32,7 @@
 #include "modules/crypto/CryptoResult.h"
 
 #include "V8Key.h" // Must precede ScriptPromiseResolver.h
+#include "V8KeyPair.h" // Must precede ScriptPromiseResolver.h
 #include "bindings/v8/custom/V8ArrayBufferCustom.h" // Must precede ScriptPromiseResolver.h
 #include "bindings/v8/ScriptPromiseResolver.h"
 #include "modules/crypto/Key.h"
@@ -78,6 +79,12 @@ void CryptoResult::completeWithKey(const WebKit::WebCryptoKey& key)
     finish();
 }
 
+void CryptoResult::completeWithKeyPair(const WebKit::WebCryptoKey& publicKey, const WebKit::WebCryptoKey& privateKey)
+{
+    m_promiseResolver->fulfill(KeyPair::create(publicKey, privateKey));
+    finish();
+}
+
 ScriptObject CryptoResult::promise()
 {
     return m_promiseResolver->promise();