Implement Composition interface for IME API

Source/core/html/ime/InputMethodContext.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef InputMethodContext_h
 #define InputMethodContext_h
 
 #include "bindings/v8/ScriptWrappable.h"
+#include "core/editing/CompositionUnderline.h"
 #include "core/html/HTMLElement.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/RefPtr.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 class Composition;
+class InputMethodController;
 class Node;
 
 class InputMethodContext : public ScriptWrappable {
 public:
     static PassOwnPtr<InputMethodContext> create(HTMLElement*);
     ~InputMethodContext();
 
     void ref() { m_element->ref(); }
     void deref() { m_element->deref(); }
 
     Composition* composition() const;
     String locale() const;
     HTMLElement* target() const;
     void confirmComposition();
     void setCaretRectangle(Node* anchor, int x, int y, int w, int h);
     void setExclusionRectangle(Node* anchor, int x, int y, int w, int h);
 
+    String compositionText() const;
+    int selectionStart() const;
+    int selectionEnd() const;
+    const Vector<unsigned>& segments();
+
 private:
     InputMethodContext(HTMLElement*);
+    bool hasFocus() const;
+    CompositionUnderline selectedSegment() const;
+    InputMethodController& inputMethodController() const;
+
     RefPtr<Composition> m_composition;
+    Vector<unsigned> m_segments;
     HTMLElement* m_element;
 };
 
 } // namespace WebCore
 
 #endif // InputMethodContext_h