Support for the new WebCrypto digest by chunks API.

content/child/webcrypto/shared_crypto.h

Index: content/child/webcrypto/shared_crypto.h
diff --git a/content/child/webcrypto/shared_crypto.h b/content/child/webcrypto/shared_crypto.h
index 50ce592c7b99f430f51ec1089930b31cdfcd2169..c9ce1a0d1348e07d28439cc5563f0de1edda8fda 100644
--- a/content/child/webcrypto/shared_crypto.h
+++ b/content/child/webcrypto/shared_crypto.h
@@ -7,6 +7,7 @@
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebArrayBuffer.h"
 #include "third_party/WebKit/public/platform/WebCrypto.h"
@@ -86,6 +87,9 @@ CONTENT_EXPORT Status Digest(const blink::WebCryptoAlgorithm& algorithm,
                              const CryptoData& data,
                              blink::WebArrayBuffer* buffer);
 
+CONTENT_EXPORT scoped_ptr<blink::WebCryptoDigestor> CreateDigestor(
+    blink::WebCryptoAlgorithmId algorithm);
+
 CONTENT_EXPORT Status
     GenerateSecretKey(const blink::WebCryptoAlgorithm& algorithm,
                       bool extractable,