Revert of List message decryption failures on chrome://gcm-internals

components/gcm_driver/crypto/gcm_encryption_provider.cc

Index: components/gcm_driver/crypto/gcm_encryption_provider.cc
diff --git a/components/gcm_driver/crypto/gcm_encryption_provider.cc b/components/gcm_driver/crypto/gcm_encryption_provider.cc
index 5e76ac1e9d9c8276054e1a0a2b5565be97a9a123..b869deeb0ac4707e065c38691d03007af83060f7 100644
--- a/components/gcm_driver/crypto/gcm_encryption_provider.cc
+++ b/components/gcm_driver/crypto/gcm_encryption_provider.cc
@@ -28,27 +28,6 @@
     FILE_PATH_LITERAL("Encryption");
 
 }  // namespace
-
-std::string GCMEncryptionProvider::ToDecryptionFailureDetailsString(
-    DecryptionFailure reason) {
-  switch(reason) {
-    case DECRYPTION_FAILURE_UNKNOWN:
-      return "Unknown failure";
-    case DECRYPTION_FAILURE_INVALID_ENCRYPTION_HEADER:
-      return "Invalid format for the Encryption header";
-    case DECRYPTION_FAILURE_INVALID_CRYPTO_KEY_HEADER:
-      return "Invalid format for the Crypto-Key header";
-    case DECRYPTION_FAILURE_NO_KEYS:
-      return "There are no associated keys with the subscription";
-    case DECRYPTION_FAILURE_INVALID_PUBLIC_KEY:
-      return "The public key in the Crypto-Key header is invalid";
-    case DECRYPTION_FAILURE_INVALID_PAYLOAD:
-      return "AES-GCM decryption failed";
-  }
-
-  NOTREACHED();
-  return "(invalid reason)";
-}
 
 GCMEncryptionProvider::GCMEncryptionProvider()
     : weak_ptr_factory_(this) {