linux_aura: Compile ash into chrome.

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 709336ffaad941574af07bca9ee0fa40e4d84f99..c734e84bc4542ea82c6330739836569057dd4137 100644
--- a/ash/accelerators/magnifier_key_scroller.cc
+++ b/ash/accelerators/magnifier_key_scroller.cc
@@ -17,9 +17,13 @@ bool magnifier_key_scroller_enabled = false;
 
 // static
 bool MagnifierKeyScroller::IsEnabled() {
-  return (magnifier_key_scroller_enabled ||
-          CommandLine::ForCurrentProcess()->HasSwitch(
-              switches::kAshEnableMagnifierKeyScroller)) &&
+  bool has_switch = false;
+#if defined(OS_CHROMEOS)
+  has_switch = CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kAshEnableMagnifierKeyScroller);
+#endif
+
+  return (magnifier_key_scroller_enabled || has_switch) &&
       ash::Shell::GetInstance()->magnification_controller()->IsEnabled();
 }