Fixes some memory leaks in //runtime/bin

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"
 
 
@@ skipping 14 matching lines @@
   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.
+  // Extracts the environment variables for the current process.  The array of
+  // strings is Dart_ScopeAllocated. 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);
 
-  static char* ResolveExecutablePath();
+  static const char* ResolveExecutablePath();
 
   // Stores the executable name.
   static void SetExecutableName(const char* executable_name) {
     executable_name_ = executable_name;
   }
   static const char* GetExecutableName() {
     return executable_name_;
   }
   static const char* GetResolvedExecutableName() {
     if (resolved_executable_name_ == NULL) {
@@ skipping 27 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_