Provide a std::vector compliant empty() method for WebVector.

third_party/WebKit/public/platform/WebCryptoAlgorithmParams.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 170 matching lines @@
   WebCryptoAesGcmParams(WebVector<unsigned char> iv,
                         bool hasAdditionalData,
                         WebVector<unsigned char> additionalData,
                         bool hasTagLengthBits,
                         unsigned char tagLengthBits)
       : m_iv(std::move(iv)),
         m_hasAdditionalData(hasAdditionalData),
         m_optionalAdditionalData(std::move(additionalData)),
         m_hasTagLengthBits(hasTagLengthBits),
         m_optionalTagLengthBits(tagLengthBits) {
-    DCHECK(hasAdditionalData || m_optionalAdditionalData.isEmpty());
+    DCHECK(hasAdditionalData || m_optionalAdditionalData.empty());
     DCHECK(hasTagLengthBits || !tagLengthBits);
   }
 
   virtual WebCryptoAlgorithmParamsType type() const {
     return WebCryptoAlgorithmParamsTypeAesGcmParams;
   }
 
   const WebVector<unsigned char>& iv() const { return m_iv; }
 
   bool hasAdditionalData() const { return m_hasAdditionalData; }
@@ skipping 61 matching lines @@
  private:
   const unsigned m_modulusLengthBits;
   const WebVector<unsigned char> m_publicExponent;
   const WebCryptoAlgorithm m_hash;
 };
 
 class WebCryptoRsaOaepParams : public WebCryptoAlgorithmParams {
  public:
   WebCryptoRsaOaepParams(bool hasLabel, WebVector<unsigned char> label)
       : m_hasLabel(hasLabel), m_optionalLabel(std::move(label)) {
-    DCHECK(hasLabel || m_optionalLabel.isEmpty());
+    DCHECK(hasLabel || m_optionalLabel.empty());
   }
 
   virtual WebCryptoAlgorithmParamsType type() const {
     return WebCryptoAlgorithmParamsTypeRsaOaepParams;
   }
 
   bool hasLabel() const { return m_hasLabel; }
   const WebVector<unsigned char>& optionalLabel() const {
     return m_optionalLabel;
   }
@@ skipping 127 matching lines @@
   unsigned iterations() const { return m_iterations; }
 
  private:
   const WebVector<unsigned char> m_salt;
   const unsigned m_iterations;
 };
 
 }  // namespace blink
 
 #endif