Revert r43217, r43215, r43208, r43207, and r43202.

runtime/bin/platform.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef BIN_PLATFORM_H_
 #define BIN_PLATFORM_H_
 
 #include "bin/builtin.h"
 
 
 namespace dart {
 namespace bin {
 
 class Platform {
  public:
   // Perform platform specific initialization.
   static bool Initialize();
 
   // Returns the number of processors on the machine.
   static int NumberOfProcessors();
 
   // Returns a string representing the operating system ("linux",
   // "macos" or "windows"). The returned string should not be
   // deallocated by the caller.
   static const char* OperatingSystem();
 
-  // Returns a string representing the operating system's shared library
-  // extension (e.g. 'so', 'dll', ...). The returned string should not be
-  // deallocated by the caller.
-  static const char* LibraryExtension();
-
   // Extracts the local hostname.
   static bool LocalHostname(char* buffer, intptr_t buffer_length);
 
   // Extracts the environment variables for the current process.  The
   // array of strings returned must be deallocated using
   // FreeEnvironment. The number of elements in the array is returned
   // in the count argument.
   static char** Environment(intptr_t* count);
   static void FreeEnvironment(char** env, intptr_t count);
 
@@ skipping 32 matching lines @@
   static char** argv_;  // VM flags are argv_[1 ... script_index_ - 1]
 
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(Platform);
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_PLATFORM_H_