WIP: Ash IME support

win8/metro_driver/ime/keyevent_filter.h

Index: win8/metro_driver/ime/keyevent_filter.h
diff --git a/win8/metro_driver/ime/keyevent_filter.h b/win8/metro_driver/ime/keyevent_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..50f5b7b0262798c6f1909fc27e512514f08c936e
--- /dev/null
+++ b/win8/metro_driver/ime/keyevent_filter.h
@@ -0,0 +1,20 @@
+// Copyright (c) 2013 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 WIN8_METRO_DRIVER_IME_KEYEVENT_FILTER_H_
+#define WIN8_METRO_DRIVER_IME_KEYEVENT_FILTER_H_
+
+namespace metro_driver {
+
+// Installs/Uninstalls key event filter, which generates a VK_PROCESSKEY event
+// whenever a key event is handled and eaten by an IME to emulate conventional
+// key event sequence in IMM32 era.
+// Note: this is an optional feature. TSF is still functional even if this event
+// filter is not installed.
+bool InstallKeyEventFilter();
+void UninstallKeyEventFilter();
+
+}  // namespace metro_driver
+
+#endif  // WIN8_METRO_DRIVER_IME_KEYEVENT_FILTER_H_