[Mac] Implement the system dictionary popup by implementing NSTextInput methods.

chrome/renderer/text_input_client_observer.h

Index: chrome/renderer/text_input_client_observer.h
diff --git a/chrome/renderer/text_input_client_observer.h b/chrome/renderer/text_input_client_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..bbd265a114a4ad23a4a150e03590156194a14c5d
--- /dev/null
+++ b/chrome/renderer/text_input_client_observer.h
@@ -0,0 +1,41 @@
+// Copyright (c) 2011 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 CHROME_RENDERER_TEXT_INPUT_CLIENT_OBSERVER_H_
+#define CHROME_RENDERER_TEXT_INPUT_CLIENT_OBSERVER_H_
+
+#include "base/basictypes.h"
+#include "build/build_config.h"
+#include "content/renderer/render_view_observer.h"
+#include "ui/base/range/range.h"
+#include "ui/gfx/point.h"
+
+namespace WebKit {
+class WebView;
+}
+
+// This is the renderer-side message filter that generates the replies for the
+// messages sent by the TextInputClientMac. See
+// chrome/browser/renderer_host/text_input_client_mac.h for more information.
+class TextInputClientObserver : public RenderViewObserver {
+ public:
+  explicit TextInputClientObserver(RenderView* render_view);
+  virtual ~TextInputClientObserver();
+
+  // RenderViewObserver overrides:
+  virtual bool OnMessageReceived(const IPC::Message& message);
+
+ private:
+  // Returns the WebView of the RenderView.
+  WebKit::WebView* webview();
+
+  // IPC Message handlers:
+  void OnCharacterIndexForPoint(gfx::Point point);
+  void OnFirstRectForCharacterRange(ui::Range range);
+  void OnStringForRange(ui::Range range);
+
+  DISALLOW_COPY_AND_ASSIGN(TextInputClientObserver);
+};
+
+#endif  // CHROME_RENDERER_TEXT_INPUT_CLIENT_OBSERVER_H_