Use Drive v2 API: enable behind --enable-drive-api flag

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_
 #pragma once
 
@@ skipping 125 matching lines @@
 extern const char kEnableAutofillFeedback[];
 extern const char kEnableAutologin[];
 extern const char kEnableBenchmarking[];
 extern const char kEnableBundledPpapiFlash[];
 extern const char kEnableChromeToMobile[];
 extern const char kEnableCloudPolicyService[];
 extern const char kEnableCloudPrintProxy[];
 extern const char kEnableConnectBackupJobs[];
 extern const char kEnableCrxlessWebApps[];
 extern const char kEnableDevToolsExperiments[];
+extern const char kEnableDriveV2Api[];
 extern const char kEnableEasyOffStoreExtensionInstall[];
 extern const char kEnableExperimentalExtensionApis[];
 extern const char kEnableExtensionActivityLogging[];
 extern const char kEnableExtensionActivityUI[];
 extern const char kEnableExtensionTimelineApi[];
 extern const char kEnableFileCookies[];
 extern const char kEnableHttpPipelining[];
 extern const char kEnableHtml5Camera[];
 extern const char kEnableInstantExtendedAPI[];
 extern const char kEnableIPv6[];
@@ skipping 270 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_