Remove now unnecessary const_casts.

content/child/webcrypto/openssl/rsa_ssa_openssl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/child/webcrypto/crypto_data.h"
 #include "content/child/webcrypto/openssl/key_openssl.h"
 #include "content/child/webcrypto/openssl/rsa_key_openssl.h"
 #include "content/child/webcrypto/openssl/util_openssl.h"
 #include "content/child/webcrypto/status.h"
 #include "crypto/openssl_util.h"
@@ skipping 79 matching lines @@
       return status;
 
     if (1 != EVP_DigestVerifyInit(ctx.get(), NULL, digest, NULL, public_key))
       return Status::OperationError();
 
     if (1 !=
         EVP_DigestVerifyUpdate(ctx.get(), data.bytes(), data.byte_length())) {
       return Status::OperationError();
     }
 
-    // This function takes a non-const pointer to the signature, however does
-    // not mutate it, so casting is safe.
-    // Also note that the return value can be:
+    // Note that the return value can be:
     //   1 --> Success
     //   0 --> Verification failed
     //  <0 --> Operation error
     int rv = EVP_DigestVerifyFinal(ctx.get(),
-                                   const_cast<uint8_t*>(signature.bytes()),
+                                   signature.bytes(),
                                    signature.byte_length());
     *signature_match = rv == 1;
     return rv >= 0 ? Status::Success() : Status::OperationError();
   }
 };
 
 }  // namespace
 
 AlgorithmImplementation* CreatePlatformRsaSsaImplementation() {
   return new RsaSsaImplementation;
 }
 
 }  // namespace webcrypto
 
 }  // namespace content