libchrome: Several upstreamable fixes from libchrome

base/files/file_path.cc

 // Copyright (c) 2012 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 "base/files/file_path.h"
 
 #include <string.h>
 #include <algorithm>
 
 #include "base/logging.h"
@@ skipping 35 matching lines @@
 // returns npos.
 StringPieceType::size_type FindDriveLetter(StringPieceType path) {
 #if defined(FILE_PATH_USES_DRIVE_LETTERS)
   // This is dependent on an ASCII-based character set, but that's a
   // reasonable assumption.  iswalpha can be too inclusive here.
   if (path.length() >= 2 && path[1] == L':' &&
       ((path[0] >= L'A' && path[0] <= L'Z') ||
        (path[0] >= L'a' && path[0] <= L'z'))) {
     return 1;
   }
+#else
+  (void)path;  // Avoid an unused warning.
 #endif  // FILE_PATH_USES_DRIVE_LETTERS
   return StringType::npos;
 }
 
 #if defined(FILE_PATH_USES_DRIVE_LETTERS)
 bool EqualDriveLetterCaseInsensitive(StringPieceType a, StringPieceType b) {
   size_t a_letter_pos = FindDriveLetter(a);
   size_t b_letter_pos = FindDriveLetter(b);
 
   if (a_letter_pos == StringType::npos || b_letter_pos == StringType::npos)
@@ skipping 1246 matching lines @@
 FilePath FilePath::NormalizePathSeparatorsTo(CharType separator) const {
 #if defined(FILE_PATH_USES_WIN_SEPARATORS)
   DCHECK_NE(kSeparators + kSeparatorsLength,
             std::find(kSeparators, kSeparators + kSeparatorsLength, separator));
   StringType copy = path_;
   for (size_t i = 0; i < kSeparatorsLength; ++i) {
     std::replace(copy.begin(), copy.end(), kSeparators[i], separator);
   }
   return FilePath(copy);
 #else
+  (void)separator;  // Avoid an unused warning.
   return *this;
 #endif
 }
 
 #if defined(OS_ANDROID)
 bool FilePath::IsContentUri() const {
   return StartsWith(path_, "content://", base::CompareCase::INSENSITIVE_ASCII);
 }
 #endif
 
 }  // namespace base