Add WARN_UNUSED_RESULT to crypto/hmac.h

chrome/common/net/gaia/oauth_request_signer.cc

 // Copyright (c) 2011 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 "chrome/common/net/gaia/oauth_request_signer.h"
 
 #include <cctype>
 #include <cstddef>
 #include <cstdlib>
 #include <cstring>
@@ skipping 186 matching lines @@
 }
 
 // Creates the value for the oauth_signature parameter when the
 // oauth_signature_method is HMAC-SHA1.
 bool SignHmacSha1(const std::string& text,
                   const std::string& key,
                   std::string* signature_return) {
   crypto::HMAC hmac(crypto::HMAC::SHA1);
   DCHECK(hmac.DigestLength() == kHmacDigestLength);
   unsigned char digest[kHmacDigestLength];
-  hmac.Init(key);
-  bool result = hmac.Sign(text, digest, kHmacDigestLength) &&
+  bool result = hmac.Init(key) &&
+      hmac.Sign(text, digest, kHmacDigestLength) &&
       base::Base64Encode(std::string(reinterpret_cast<const char*>(digest),
                                      kHmacDigestLength),
                          signature_return);
   return result;
 }
 
 // Creates the value for the oauth_signature parameter when the
 // oauth_signature_method is PLAINTEXT.
 //
 // Not yet implemented, and might never be.
@@ skipping 182 matching lines @@
         signed_text += base_parameters + '&' + kOAuthSignatureLabel + '=' +
             Encode(signature);
         break;
       default:
         NOTREACHED();
     }
     *signed_text_return = signed_text;
   }
   return is_signed;
 }