Added flag for alternate launcher settings (remaining changes to come).

ash/ash_switches.h

Index: ash/ash_switches.h
diff --git a/ash/ash_switches.h b/ash/ash_switches.h
index a112592c19999bf06510c0ef4dd380fa2d096b17..c059cb5f8032ecbaba62f82a6b7cf9e33210f2f7 100644
--- a/ash/ash_switches.h
+++ b/ash/ash_switches.h
@@ -50,6 +50,7 @@ ASH_EXPORT extern const char kAshHostWindowBounds[];
 ASH_EXPORT extern const char kAshImmersiveHideTabIndicators[];
 ASH_EXPORT extern const char kAshSecondaryDisplayLayout[];
 ASH_EXPORT extern const char kAshTouchHud[];
+ASH_EXPORT extern const char kAshUseAlternateShelfLayout[];
 ASH_EXPORT extern const char kAshUseFirstDisplayAsInternal[];
 ASH_EXPORT extern const char kAuraLegacyPowerButton[];
 #if defined(OS_WIN)
@@ -63,6 +64,9 @@ ASH_EXPORT bool UseNewAudioHandler();
 // Returns true if we should show the audio device switching UI.
 ASH_EXPORT bool ShowAudioDeviceMenu();
 
+// Returns true if the alternate shelf layout should be used.
+ASH_EXPORT bool UseAlternateShelfLayout();
+
 }  // namespace switches
 }  // namespace ash