Cleanup: Better constify some strings in base.

base/nix/xdg_util_unittest.cc

 // 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.
 
 #include "base/nix/xdg_util.h"
 
 #include "base/environment.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using ::testing::_;
 using ::testing::Return;
 using ::testing::SetArgumentPointee;
 using ::testing::StrEq;
 
 namespace base {
 namespace nix {
 
 namespace {
 
 class MockEnvironment : public Environment {
  public:
   MOCK_METHOD2(GetVar, bool(const char*, std::string* result));
   MOCK_METHOD2(SetVar, bool(const char*, const std::string& new_value));
   MOCK_METHOD1(UnSetVar, bool(const char*));
 };
 
-const char* kGnome = "gnome";
-const char* kKDE4 = "kde4";
-const char* kKDE = "kde";
-const char* kXFCE = "xfce";
+const char* const kGnome = "gnome";
+const char* const kKDE4 = "kde4";
+const char* const kKDE = "kde";
+const char* const kXFCE = "xfce";
 
 }  // namespace
 
 TEST(XDGUtilTest, GetDesktopEnvironmentGnome) {
   MockEnvironment getter;
   EXPECT_CALL(getter, GetVar(_, _)).WillRepeatedly(Return(false));
   EXPECT_CALL(getter, GetVar(StrEq("DESKTOP_SESSION"), _))
       .WillOnce(DoAll(SetArgumentPointee<1>(kGnome), Return(true)));
 
   EXPECT_EQ(DESKTOP_ENVIRONMENT_GNOME,
@@ skipping 25 matching lines @@
   EXPECT_CALL(getter, GetVar(_, _)).WillRepeatedly(Return(false));
   EXPECT_CALL(getter, GetVar(StrEq("DESKTOP_SESSION"), _))
       .WillOnce(DoAll(SetArgumentPointee<1>(kXFCE), Return(true)));
 
   EXPECT_EQ(DESKTOP_ENVIRONMENT_XFCE,
             GetDesktopEnvironment(&getter));
 }
 
 }  // namespace nix
 }  // namespace base