Try again: Add proxy config (using gnome-network-preferences)

base/linux_util.h

 // Copyright (c) 2009 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_LINUX_UTIL_H__
 #define BASE_LINUX_UTIL_H__
 
 #include <stdint.h>
 
 #include <string>
 
 namespace base {
 
 // Makes a copy of |pixels| with the ordering changed from BGRA to RGBA.
 // The caller is responsible for free()ing the data. If |stride| is 0,
 // it's assumed to be 4 * |width|.
 uint8_t* BGRAToRGBA(const uint8_t* pixels, int width, int height, int stride);
 
 // Get the Linux Distro if we can, or return "Unknown", similar to
 // GetWinVersion() in base/win_util.h.
 std::string GetLinuxDistro();
 
+// These are used to derive mocks for unittests.
+class EnvironmentVariableGetter {
+ public:
+  virtual ~EnvironmentVariableGetter() {}
+  // 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;
+
+  // Create an instance of EnvironmentVariableGetter
+  static EnvironmentVariableGetter* Create();
+};
+
+// Return true if we appear to be running under Gnome and should attempt to use
+// some prefrences from the desktop environment (eg proxy settings),
+// If someone adds support for other environments, this function could be
+// replaced with one that returns an enum so we an specify Gnome, KDE, etc.
+bool UseGnomeForSettings(EnvironmentVariableGetter* env_var_getter);
+
 }  // namespace base
 
 #endif  // BASE_LINUX_UTIL_H__