Delete unused code in chrome/common or mark them as platform specific.

chrome/installer/util/util_constants.cc

 // Copyright (c) 2012 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 "chrome/installer/util/util_constants.h"
 
 namespace installer {
 
 namespace switches {
 
@@ skipping 168 matching lines @@
 // specified as command line arguments following the --patch switch.
 // Ex: --patch=courgette --input_file='input' --patch_file='patch'
 //        --output_file='output'
 const char kPatch[] = "patch";
 const char kInputFile[] = "input-file";
 const char kPatchFile[] = "patch-file";
 const char kOutputFile[] = "output-file";
 
 }  // namespace switches
 
+namespace env_vars {
+
+// The presence of this environment variable with a value of 1 implies that
+// setup.exe should run as a system installation regardless of what is on the
+// command line.
+const char kGoogleUpdateIsMachineEnvVar[] = "GoogleUpdateIsMachine";
+
+}  // namespace env_vars
+
 // The Active Setup executable will be an identical copy of setup.exe; this is
 // necessary because Windows' installer detection heuristics (which include
 // things like process name being "setup.exe") will otherwise force elevation
 // for non-admin users when setup.exe is launched. This is mitigated by adding
 // requestedExecutionLevel="asInvoker" to setup.exe's manifest on Vista+, but
 // there is no such manifest entry on Windows XP (which results in
 // crbug.com/166473).
 // TODO(gab): Rename setup.exe itself altogether and use the same binary for
 // Active Setup.
 const wchar_t kActiveSetupExe[] = L"chrmstp.exe";
@@ skipping 43 matching lines @@
 const wchar_t kChromeChannelBeta[] = L"beta";
 const wchar_t kChromeChannelStable[] = L"";
 const wchar_t kChromeChannelStableExplicit[] = L"stable";
 
 const size_t kMaxAppModelIdLength = 64U;
 
 const char kCourgette[] = "courgette";
 const char kBsdiff[] = "bsdiff";
 
 }  // namespace installer