Implement IsAsciiUpper and IsAsciiLower in base/strings/string_util.h

url/url_file.h

 // Copyright 2013 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.
 
 #ifndef URL_URL_FILE_H_
 #define URL_URL_FILE_H_
 
 // Provides shared functions used by the internals of the parser and
 // canonicalizer for file URLs. Do not use outside of these modules.
 
+#include "base/strings/string_util.h"
 #include "url/url_parse_internal.h"
 
 namespace url {
 
 #ifdef WIN32
 
 // We allow both "c:" and "c|" as drive identifiers.
 inline bool IsWindowsDriveSeparator(base::char16 ch) {
   return ch == ':' || ch == '|';
 }
-inline bool IsWindowsDriveLetter(base::char16 ch) {
-  return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z');
-}
 
 #endif  // WIN32
 
 // Returns the index of the next slash in the input after the given index, or
 // spec_len if the end of the input is reached.
 template<typename CHAR>
 inline int FindNextSlash(const CHAR* spec, int begin_index, int spec_len) {
   int idx = begin_index;
   while (idx < spec_len && !IsURLSlash(spec[idx]))
     idx++;
   return idx;
 }
 
 #ifdef WIN32
 
 // Returns true if the start_offset in the given spec looks like it begins a
 // drive spec, for example "c:". This function explicitly handles start_offset
 // values that are equal to or larger than the spec_len to simplify callers.
 //
 // If this returns true, the spec is guaranteed to have a valid drive letter
 // plus a colon starting at |start_offset|.
 template<typename CHAR>
 inline bool DoesBeginWindowsDriveSpec(const CHAR* spec, int start_offset,
                                       int spec_len) {
   int remaining_len = spec_len - start_offset;
   if (remaining_len < 2)
     return false;  // Not enough room.
-  if (!IsWindowsDriveLetter(spec[start_offset]))
+  if (!base::IsAsciiAlpha(spec[start_offset]))
     return false;  // Doesn't start with a valid drive letter.
   if (!IsWindowsDriveSeparator(spec[start_offset + 1]))
     return false;  // Isn't followed with a drive separator.
   return true;
 }
 
 // Returns true if the start_offset in the given text looks like it begins a
 // UNC path, for example "\\". This function explicitly handles start_offset
 // values that are equal to or larger than the spec_len to simplify callers.
 //
@@ skipping 12 matching lines @@
   if (strict_slashes)
     return text[start_offset] == '\\' && text[start_offset + 1] == '\\';
   return IsURLSlash(text[start_offset]) && IsURLSlash(text[start_offset + 1]);
 }
 
 #endif  // WIN32
 
 }  // namespace url
 
 #endif  // URL_URL_FILE_H_