ash: Remove OS_CHROMEOS ifdefs from accelerator files

ash/accelerators/magnifier_key_scroller.cc

Index: ash/accelerators/magnifier_key_scroller.cc
diff --git a/ash/accelerators/magnifier_key_scroller.cc b/ash/accelerators/magnifier_key_scroller.cc
index d74cbfbcdbf80417d1f3e239559d44f8d545bf88..342edbe5ceb2a56b9a85dbae5c5dcb2b6ea44f52 100644
--- a/ash/accelerators/magnifier_key_scroller.cc
+++ b/ash/accelerators/magnifier_key_scroller.cc
@@ -20,11 +20,8 @@ bool magnifier_key_scroller_enabled = false;
 
 // static
 bool MagnifierKeyScroller::IsEnabled() {
-  bool has_switch = false;
-#if defined(OS_CHROMEOS)
-  has_switch = base::CommandLine::ForCurrentProcess()->HasSwitch(
+  bool has_switch = base::CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kAshEnableMagnifierKeyScroller);
-#endif
 
   return (magnifier_key_scroller_enabled || has_switch) &&
          ash::Shell::GetInstance()->magnification_controller()->IsEnabled();