Enable basic IME functionality under Ash on Windows

win8/metro_driver/ime/text_service_delegate.h

Index: win8/metro_driver/ime/text_service_delegate.h
diff --git a/win8/metro_driver/ime/text_service_delegate.h b/win8/metro_driver/ime/text_service_delegate.h
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+++ b/win8/metro_driver/ime/text_service_delegate.h
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+// 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_TEXT_SERVICE_DELEGATE_H_
+#define WIN8_METRO_DRIVER_IME_TEXT_SERVICE_DELEGATE_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/strings/string16.h"
+
+namespace metro_viewer {
+struct UnderlineInfo;
+}
+
+namespace metro_driver {
+
+// A delegate which works together with virtual text service.
+// Objects that implement this delegate will receive notifications from a
+// virtual text service whenever an IME updates the composition or commits text.
+class TextServiceDelegate {
+ public:
+  virtual ~TextServiceDelegate() {}
+
+  // Called when on-going composition is updated. An empty |text| represents
+  // that the composition is canceled.
+  virtual void OnCompositionChanged(
+      const string16& text,
+      int32 selection_start,
+      int32 selection_end,
+      const std::vector<metro_viewer::UnderlineInfo>& underlines) = 0;
+
+  // Called when |text| is committed.
+  virtual void OnTextCommitted(const string16& text) = 0;
+};
+
+}  // namespace metro_driver
+
+#endif  // WIN8_METRO_DRIVER_IME_TEXT_SERVICE_DELEGATE_H_