[webcrypto] Add JWK RSA public key export for NSS.

content/child/webcrypto/platform_crypto.h

Index: content/child/webcrypto/platform_crypto.h
diff --git a/content/child/webcrypto/platform_crypto.h b/content/child/webcrypto/platform_crypto.h
index 3f884d60640e91cabac0ee781666af11f45cb319..499ac4c518b11e6e72574335263354321a30508f 100644
--- a/content/child/webcrypto/platform_crypto.h
+++ b/content/child/webcrypto/platform_crypto.h
@@ -5,6 +5,7 @@
 #ifndef CONTENT_CHILD_WEBCRYPTO_PLATFORM_CRYPTO_H_
 #define CONTENT_CHILD_WEBCRYPTO_PLATFORM_CRYPTO_H_
 
+#include <vector>
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "third_party/WebKit/public/platform/WebArrayBuffer.h"
@@ -177,6 +178,12 @@ Status ExportKeyRaw(SymKey* key, blink::WebArrayBuffer* buffer);
 Status ExportKeySpki(PublicKey* key, blink::WebArrayBuffer* buffer);
 
 // Preconditions:
+//  * |key| is non-null.
+Status ExportRsaPublicKey(PublicKey* key,
+                          std::vector<uint8>* modulus,
+                          std::vector<uint8>* public_exponent);
+
+// Preconditions:
 //  * |wrapping_key| is non-null
 //  * |key| is non-null
 Status WrapSymKeyAesKw(SymKey* wrapping_key,