aura: Fix IME interaction in content-shell in chromeos build.

ui/aura/test/input_method_glue.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_AURA_TEST_INPUT_METHOD_GLUE_H_
+#define UI_AURA_TEST_INPUT_METHOD_GLUE_H_
+
+#include "ui/base/ime/input_method_delegate.h"
+#include "ui/events/event_handler.h"
+
+namespace aura {
+
+class WindowTreeHost;
+
+class InputMethodGlue : public ui::EventHandler,
+                        public ui::internal::InputMethodDelegate {
+ public:
+  explicit InputMethodGlue(aura::WindowTreeHost* host);
+  ~InputMethodGlue() override;
+
+ private:
+  // ui::EventHandler:
+  void OnKeyEvent(ui::KeyEvent* key) override;
+
+  // ui::internal::InputMethodDelegate:
+  ui::EventDispatchDetails DispatchKeyEventPostIME(ui::KeyEvent* key) override;

[Shu Chen, 2016/07/21 00:28:53]

Why does InputMethodGlue need to inherit from InputMethodDelegate, and why this
override is necessary?

[sadrul, 2016/07/21 00:51:32]

The override dispatches the event back to the WindowTreeHost, which is what's
supposed to happen. The override here is to make sure this Glue does not attempt
to process the event again (this is aking to SetPostIME used in ash:
https://cs.chromium.org/chromium/src/ash/ime/input_method_event_handler.cc?sq...)

+
+  aura::WindowTreeHost* host_;
+  bool processing_ime_event_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(InputMethodGlue);
+};
+
+}  // namespace aura
+
+#endif  // UI_AURA_TEST_INPUT_METHOD_GLUE_H_