AppShell: Create input method and handle key events

extensions/shell/browser/input_method_event_handler.h

Index: extensions/shell/browser/input_method_event_handler.h
diff --git a/extensions/shell/browser/input_method_event_handler.h b/extensions/shell/browser/input_method_event_handler.h
new file mode 100644
index 0000000000000000000000000000000000000000..45a4443641670598d5a9ae4b0252e3645306337c
--- /dev/null
+++ b/extensions/shell/browser/input_method_event_handler.h
@@ -0,0 +1,42 @@
+// 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 EXTENSIONS_SHELL_BROWSER_INPUT_METHOD_EVENT_HANDLER_H_
+#define EXTENSIONS_SHELL_BROWSER_INPUT_METHOD_EVENT_HANDLER_H_
+
+#include "base/macros.h"
+#include "ui/events/event_handler.h"
+
+namespace ui {
+class InputMethod;
+class KeyEvent;
+}
+
+namespace extensions {
+
+// Basic EventHandler for dispatching key events.
+class InputMethodEventHandler : public ui::EventHandler {
+ public:
+  explicit InputMethodEventHandler(ui::InputMethod* input_method);
+  ~InputMethodEventHandler() override;
+
+  // True when an event is dispatched within DispatchKeyEventPostIME(), meaning

[Rahul Chaturvedi, 2016/12/15 22:42:46]

nit: This comment should be on the field declaration. This method is a
self-documenting setter.

[michaelpg, 2016/12/15 23:55:52]

Done.

+  // it has already been processed by the input method.
+  void SetPostIME(bool post_ime);

[Rahul Chaturvedi, 2016/12/15 22:42:46]

nit: Since this is a setter, set_post_ime(bool post_ime)?

[michaelpg, 2016/12/15 23:55:52]

Done.

+
+ private:
+  // ui::EventHandler:
+  void OnKeyEvent(ui::KeyEvent* event) override;
+
+  // The input method to pass events. Should outlive this handler.
+  ui::InputMethod* input_method_;
+
+  bool post_ime_;
+
+  DISALLOW_COPY_AND_ASSIGN(InputMethodEventHandler);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_SHELL_BROWSER_METHOD_EVENT_HANDLER_H_