Skip base::string16 if not necessary for WebString <-> ASCII conversion

third_party/WebKit/public/platform/WebString.h

 /*
  * Copyright (C) 2009 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 82 matching lines @@
 
   BLINK_COMMON_EXPORT std::string latin1() const;
 
   BLINK_COMMON_EXPORT static WebString fromLatin1(const WebLChar* data,
                                                   size_t length);
 
   static WebString fromLatin1(const std::string& s) {
     return fromLatin1(reinterpret_cast<const WebLChar*>(s.data()), s.length());
   }
 
+  // This asserts if the string contains non-ascii characters.
+  // Use this rather than calling base::UTF16ToASCII() which always incurs
+  // (likely unnecessary) string16 conversion.
+  BLINK_COMMON_EXPORT std::string ascii() const;
+
+  // Use this rather than calling base::IsStringASCII().
+  BLINK_COMMON_EXPORT bool containsOnlyASCII() const;
+
+  // Does same as fromLatin1 but asserts if the given string has non-ascii char.
+  BLINK_COMMON_EXPORT static WebString fromASCII(const std::string&);
+
   template <int N>
   WebString(const char (&data)[N]) {
     assign(fromUTF8(data, N - 1));
   }
 
   template <int N>
   WebString& operator=(const char (&data)[N]) {
     assign(fromUTF8(data, N - 1));
     return *this;
   }
@@ skipping 71 matching lines @@
   return a.equals(b);
 }
 
 inline bool operator!=(const WebString& a, const WebString& b) {
   return !(a == b);
 }
 
 }  // namespace blink
 
 #endif