First cut at custom user style sheets.

chrome/common/chrome_switches.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.
 
 // Defines all the command-line switches used by Chrome.
 
 #ifndef CHROME_COMMON_CHROME_SWITCHES_H_
 #define CHROME_COMMON_CHROME_SWITCHES_H_
 
 #include "build/build_config.h"
@@ skipping 84 matching lines @@
 extern const char kEnablePrivacyBlacklists[];
 extern const char kEnableRendererAccessibility[];
 extern const char kEnableSeccompSandbox[];
 extern const char kEnableStatsTable[];
 extern const char kEnableSync[];
 extern const char kEnableSyncAutofill[];
 extern const char kEnableSyncBookmarks[];
 extern const char kEnableSyncPreferences[];
 extern const char kEnableTabbedBookmarkManager[];
 extern const char kEnableUserDataDirProfiles[];
+extern const char kEnableUserStyleSheet[];
 extern const char kEnableVerticalTabs[];
 extern const char kEnableVideoLayering[];
 extern const char kEnableWatchdog[];
 extern const char kExperimentalSpellcheckerFeatures[];
 extern const char kExplicitlyAllowedPorts[];
 extern const char kExtensionProcess[];
 extern const char kExtensionsUpdateFrequency[];
 extern const char kFileDescriptorLimit[];
 extern const char kFirstRun[];
 extern const char kForceFieldTestNameAndValue[];
@@ skipping 134 matching lines @@
 extern const char kGearsPluginPathOverride[];
 extern const char kInvalidateSyncLogin[];
 #endif
 
 // DON'T ADD RANDOM STUFF HERE. Put it in the main section above in
 // alphabetical order, or in one of the ifdefs (also in order in each section).
 
 }  // namespace switches
 
 #endif  // CHROME_COMMON_CHROME_SWITCHES_H_