WebCrypto: Add ECDSA algorithm (Blink side).

Source/platform/exported/WebCryptoKeyAlgorithm.cpp

Index: Source/platform/exported/WebCryptoKeyAlgorithm.cpp
diff --git a/Source/platform/exported/WebCryptoKeyAlgorithm.cpp b/Source/platform/exported/WebCryptoKeyAlgorithm.cpp
index 1648380c10dc3fba795ed0fa9e10c00e1096c973..bef587d0d25dbd6e796cacba6688ed7e2bc256b6 100644
--- a/Source/platform/exported/WebCryptoKeyAlgorithm.cpp
+++ b/Source/platform/exported/WebCryptoKeyAlgorithm.cpp
@@ -88,6 +88,11 @@ WebCryptoKeyAlgorithm WebCryptoKeyAlgorithm::createRsaHashed(WebCryptoAlgorithmI
     return WebCryptoKeyAlgorithm(id, adoptPtr(new WebCryptoRsaHashedKeyAlgorithmParams(modulusLengthBits, publicExponent, publicExponentSize, createHash(hash))));
 }
 
+WebCryptoKeyAlgorithm WebCryptoKeyAlgorithm::createEc(WebCryptoAlgorithmId id, WebCryptoNamedCurve namedCurve)
+{
+    return WebCryptoKeyAlgorithm(id, adoptPtr(new WebCryptoEcKeyAlgorithmParams(namedCurve)));
+}
+
 bool WebCryptoKeyAlgorithm::isNull() const
 {
     return m_private.isNull();
@@ -131,6 +136,14 @@ WebCryptoRsaHashedKeyAlgorithmParams* WebCryptoKeyAlgorithm::rsaHashedParams() c
     return 0;
 }
 
+WebCryptoEcKeyAlgorithmParams* WebCryptoKeyAlgorithm::ecParams() const
+{
+    ASSERT(!isNull());
+    if (paramsType() == WebCryptoKeyAlgorithmParamsTypeEc)
+        return static_cast<WebCryptoEcKeyAlgorithmParams*>(m_private->params.get());
+    return 0;
+}
+
 void WebCryptoKeyAlgorithm::writeToDictionary(WebCryptoKeyAlgorithmDictionary* dict) const
 {
     ASSERT(!isNull());