[webcrypto] Add RSA public key SPKI import/export for NSS.

content/renderer/webcrypto/webcrypto_impl_openssl.cc

Index: content/renderer/webcrypto/webcrypto_impl_openssl.cc
diff --git a/content/renderer/webcrypto/webcrypto_impl_openssl.cc b/content/renderer/webcrypto/webcrypto_impl_openssl.cc
index f3dc397167a908698f33dd82fedc907170927f70..3543f5a3f7952124b2291df39ef7ba03951cdf84 100644
--- a/content/renderer/webcrypto/webcrypto_impl_openssl.cc
+++ b/content/renderer/webcrypto/webcrypto_impl_openssl.cc
@@ -330,14 +330,9 @@ bool WebCryptoImpl::ImportKeyInternal(
     return false;
   }
 
-  // TODO(padolph): Need to split handling for symmetric (raw or jwk format) and
-  // asymmetric (jwk, spki, or pkcs8 format) keys.
+  // TODO(padolph): Need to split handling for symmetric
   // Currently only supporting symmetric.
 
-  // TODO(padolph): jwk handling. Define precedence between jwk contents and
-  // this method's parameters, e.g. 'alg' in jwk vs algorithm.id(). Who wins if
-  // they differ? (jwk, probably)
-
   // Symmetric keys are always type secret
   blink::WebCryptoKeyType type = blink::WebCryptoKeyTypeSecret;
 
@@ -369,6 +364,17 @@ bool WebCryptoImpl::ImportKeyInternal(
   return true;
 }
 
+bool WebCryptoImpl::ExportKeyInternal(
+    blink::WebCryptoKeyFormat format,
+    const blink::WebCryptoKey& key,
+    blink::WebArrayBuffer* buffer) {
+  // TODO(padolph): Implement raw export
+  // TODO(padolph): Implement spki export
+  // TODO(padolph): Implement pkcs8 export
+  // TODO(padolph): Implement jwk export
+  return false;
+}
+
 bool WebCryptoImpl::SignInternal(
     const blink::WebCryptoAlgorithm& algorithm,
     const blink::WebCryptoKey& key,