Introduce --cancel-first-run and reduce the strength of --no-first-run.

chrome/common/chrome_switches.h

 // 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.
 
 // 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 38 matching lines @@
 extern const char kAppsNewInstallBubble[];
 extern const char kAppsNoThrob[];
 extern const char kAppsUseNativeFrame[];
 extern const char kAuthExtensionPath[];
 extern const char kAuthNegotiateDelegateWhitelist[];
 extern const char kAuthSchemes[];
 extern const char kAuthServerWhitelist[];
 extern const char kAutoLaunchAtStartup[];
 extern const char kAutomationClientChannelID[];
 extern const char kAutomationReinitializeOnChannelError[];
+extern const char kCancelFirstRun[];
 extern const char kCheckForUpdateIntervalSec[];
 extern const char kCheckCloudPrintConnectorPolicy[];
 extern const char kChromeFrame[];
 extern const char kChromeVersion[];
 extern const char kCipherSuiteBlacklist[];
 extern const char kClearTokenService[];
 extern const char kCloudPolicyInvalidationDelay[];
 extern const char kCloudPrintDeleteFile[];
 extern const char kCloudPrintFile[];
 extern const char kCloudPrintJobTitle[];
@@ skipping 390 matching lines @@
 #else
 extern const char kEnablePrintPreview[];
 #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_