Fix preparing log file name.

src/base/platform/platform.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This module contains the platform-specific code. This make the rest of the
 // code less dependent on operating system, compilers and runtime libraries.
 // This module does specifically not deal with differences between different
 // processor architecture.
 // The platform classes have the same definition for all platforms. The
 // implementation for a particular platform is put in platform_<os>.cc.
@@ skipping 124 matching lines @@
 
   // Returns the daylight savings offset for the given time.
   static double DaylightSavingsOffset(double time, TimezoneCache* cache);
 
   // Returns last OS error.
   static int GetLastError();
 
   static FILE* FOpen(const char* path, const char* mode);
   static bool Remove(const char* path);
 
+  static bool isDirectorySeparator(const char ch);
+
   // Opens a temporary file, the file is auto removed on close.
   static FILE* OpenTemporaryFile();
 
   // Log file open mode is platform-dependent due to line ends issues.
   static const char* const LogFileOpenMode;
 
   // Print output to console. This is mostly used for debugging output.
   // On platforms that has standard terminal output, the output
   // should go to stdout.
   static void Print(const char* format, ...);
@@ skipping 311 matching lines @@
   char name_[kMaxThreadNameLength];
   int stack_size_;
   Semaphore* start_semaphore_;
 
   DISALLOW_COPY_AND_ASSIGN(Thread);
 };
 
 } }  // namespace v8::base
 
 #endif  // V8_BASE_PLATFORM_PLATFORM_H_