Use precompiled headers on Windows only when a flag is set.

chrome/installer/mini_installer.gyp

 {
   'variables': {
     'version_py': '../../chrome/tools/build/version.py',
     'version_path': '../../chrome/VERSION',
     'lastchange_path': '<(SHARED_INTERMEDIATE_DIR)/build/LASTCHANGE',
     # 'branding_dir' is set in the 'conditions' section at the bottom.
     'msvs_use_common_release': 0,
     'msvs_use_common_linker_extras': 0,
   },
   'includes': [
@@ skipping 157 matching lines @@
             'variables': {
                'branding_dir': '../app/theme/chromium',
             },
           }],
         ],
       },
       'targets': [
         {
           'target_name': 'mini_installer',
           'type': 'executable',
-          'configurations': {
-            'Debug': {
-              # Disable precompiled headers for this project, to avoid
-              # linker errors when building with VS 2008.
-              #
-              # Note that putting this in the 'target_defaults'
-              # section earlier in the file does not successfully
-              # override the 'target_defaults' brought in by the
-              # build/win_precompile.gypi file, so the overriding
-              # needs to be done here, directly in the mini_installer
-              # target.
-              'msvs_precompiled_header': '',
-              'msvs_precompiled_source': '',
-            },
-          },
+
+          # Disable precompiled headers for this project, to avoid
+          # linker errors when building with VS 2008.
+          'msvs_precompiled_header': '',
+          'msvs_precompiled_source': '',
+
           'sources': [
             'mini_installer/chrome.release',
             'mini_installer/chrome_appid.cc',
           ],
           'rules': [
             {
               'rule_name': 'installer_archive',
               'extension': 'release',
               'variables': {
                 'create_installer_archive_py_path':
@@ skipping 40 matching lines @@
       'variables': {
          'branding_dir': '../app/theme/google_chrome',
       },
     }, { # else branding!="Chrome"
       'variables': {
          'branding_dir': '../app/theme/chromium',
       },
     }],
   ],
 }