ime: Remove unused member in PendingKeyEvent.

Bug: b/174612548
Change-Id: I567f592c272f6607328f4a03de551fc4582decfe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2566320
Auto-Submit: Darren Shen <shend@chromium.org>
Commit-Queue: Jing Wang <jiwan@chromium.org>
Reviewed-by: Jing Wang <jiwan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833527}

chrome/browser/chromeos/input_method/input_method_engine_base.h

@@ -266,7 +266,6 @@ class InputMethodEngineBase : virtual public ui::IMEEngineHandlerInterface,
     ~PendingKeyEvent();
 
     std::string component_id;
-    KeyboardEvent key_event;
     ui::IMEEngineHandlerInterface::KeyEventDoneCallback callback;
 
    private: