Port IsShiftDown() and variants in views::Event to aura::Event.

ui/aura/event.h

Index: ui/aura/event.h
diff --git a/ui/aura/event.h b/ui/aura/event.h
index 95ac53c39a9aa0d40e08508be9090cc340d37d90..33ade739d8ef11caf0995c08b2244adc0ce639aa 100644
--- a/ui/aura/event.h
+++ b/ui/aura/event.h
@@ -29,6 +29,13 @@ class AURA_EXPORT Event {
   const base::Time& time_stamp() const { return time_stamp_; }
   int flags() const { return flags_; }
 
+  // The following methods return true if the respective keys were pressed at
+  // the time the event was created.
+  bool IsShiftDown() const { return (flags_ & ui::EF_SHIFT_DOWN) != 0; }
+  bool IsControlDown() const { return (flags_ & ui::EF_CONTROL_DOWN) != 0; }
+  bool IsCapsLockDown() const { return (flags_ & ui::EF_CAPS_LOCK_DOWN) != 0; }
+  bool IsAltDown() const { return (flags_ & ui::EF_ALT_DOWN) != 0; }
+
  protected:
   Event(ui::EventType type, int flags);
   Event(const base::NativeEvent& native_event, ui::EventType type, int flags);