base: rename Environment::SetEnv to Environment::SetVar.

base/environment.h

 // Copyright (c) 2010 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 BASE_ENVIRONMENT_H_
 #define BASE_ENVIRONMENT_H_
 #pragma once
 
 #include <string>
 
@@ skipping 18 matching lines @@
   static Environment* Create();
 
   // Gets an environment variable's value and stores it in |result|.
   // Returns false if the key is unset.
   virtual bool GetEnv(const char* variable_name, std::string* result) = 0;
 
   // Syntactic sugar for GetEnv(variable_name, NULL);
   virtual bool HasVar(const char* variable_name);
 
   // Returns true on success, otherwise returns false.
-  virtual bool SetEnv(const char* variable_name,
+  virtual bool SetVar(const char* variable_name,
                       const std::string& new_value) = 0;
 
   // Returns true on success, otherwise returns false.
   virtual bool UnSetVar(const char* variable_name) = 0;
 };
 
 }  // namespace base
 
 #endif  // BASE_ENVIRONMENT_H_