Add --disable-drive-prefetch flag for ChromeOS.

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 355 matching lines @@
 
 #if defined(OS_ANDROID)
 extern const char kTabletUI[];
 #endif
 
 #if defined(OS_CHROMEOS)
 // Keep switches in alphabetical order.
 extern const char kAshWebUIInit[];
 extern const char kEnableCarrierSwitching[];
 extern const char kDisableBootAnimation[];
+extern const char kDisableDrivePrefetch[];
 extern const char kDisableFactoryReset[];
 extern const char kDisableGData[];
 extern const char kDisableHtml5Camera[];
 extern const char kDisableLoginAnimations[];
 extern const char kDisableNewOobe[];
 extern const char kDisableNewWallpaperUI[];
 extern const char kDisableOobeAnimation[];
 extern const char kEnableBackgroundLoader[];
 extern const char kEnableTouchpadThreeFingerClick[];
 extern const char kSkipOAuthLogin[];
@@ skipping 78 matching lines @@
 
 namespace chrome {
 
 // Returns true if the new frameless constrained window style is enabled.
 // TODO(sail): Remove this once the feature is fully baked.
 bool IsFramelessConstrainedDialogEnabled();
 
 }  // namespace chrome
 
 #endif  // CHROME_COMMON_CHROME_SWITCHES_H_