ui: Remove unused ExtendedKeyEventData.

ui/events/event.h

Index: ui/events/event.h
diff --git a/ui/events/event.h b/ui/events/event.h
index ef1bee1faec893d0627448e6b14f488e1c6f8054..850c290489025ee615ad13b23e086d402fcd0cea 100644
--- a/ui/events/event.h
+++ b/ui/events/event.h
@@ -738,17 +738,6 @@ class EVENTS_EXPORT PointerEvent : public LocatedEvent {
   PointerDetails details_;
 };
 
-// An interface that individual platforms can use to store additional data on
-// KeyEvent.
-//
-// Currently only used in mojo.
-class EVENTS_EXPORT ExtendedKeyEventData {
- public:
-  virtual ~ExtendedKeyEventData() {}
-
-  virtual ExtendedKeyEventData* Clone() const = 0;
-};
-
 // A KeyEvent is really two distinct classes, melded together due to the
 // DOM legacy of Windows key events: a keystroke event (is_char_ == false),
 // or a character event (is_char_ == true).
@@ -826,17 +815,6 @@ class EVENTS_EXPORT KeyEvent : public Event {
 
   ~KeyEvent() override;
 
-  // TODO(erg): While we transition to mojo, we have to hack around a mismatch
-  // in our event types. Our ui::Events don't really have all the data we need
-  // to process key events, and we instead do per-platform conversions with
-  // native HWNDs or XEvents. And we can't reliably send those native data
-  // types across mojo types in a cross-platform way. So instead, we set the
-  // resulting data when read across IPC boundaries.
-  void SetExtendedKeyEventData(std::unique_ptr<ExtendedKeyEventData> data);
-  const ExtendedKeyEventData* extended_key_event_data() const {
-    return extended_key_event_data_.get();
-  }
-
   // This bypasses the normal mapping from keystroke events to characters,
   // which allows an I18N virtual keyboard to fabricate a keyboard event that
   // does not have a corresponding KeyboardCode (example: U+00E1 Latin small
@@ -936,12 +914,6 @@ class EVENTS_EXPORT KeyEvent : public Event {
   // it may be set only if and when GetCharacter() or GetDomKey() is called.
   mutable DomKey key_ = DomKey::NONE;
 
-  // Parts of our event handling require raw native events (see both the
-  // windows and linux implementations of web_input_event in content/). Because
-  // mojo instead serializes and deserializes events in potentially different
-  // processes, we need to have a mechanism to keep track of this data.
-  std::unique_ptr<ExtendedKeyEventData> extended_key_event_data_;
-
   static bool IsRepeated(const KeyEvent& event);
 
   static KeyEvent* last_key_event_;