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

content/browser/renderer_host/render_widget_host.h

Index: content/browser/renderer_host/render_widget_host.h
diff --git a/content/browser/renderer_host/render_widget_host.h b/content/browser/renderer_host/render_widget_host.h
index d11043615823244e14975b87148b7566c11754f9..13aa909a93bcf07b929f366095cf93f9fe7a1e9a 100644
--- a/content/browser/renderer_host/render_widget_host.h
+++ b/content/browser/renderer_host/render_widget_host.h
@@ -31,6 +31,10 @@ namespace gfx {
 class Rect;
 }
 
+namespace ui {
+class Range;
+}
+
 namespace WebKit {
 class WebInputEvent;
 class WebMouseEvent;
@@ -475,6 +479,7 @@ class RenderWidgetHost : public IPC::Channel::Listener,
   void OnMsgSetCursor(const WebCursor& cursor);
   void OnMsgImeUpdateTextInputState(WebKit::WebTextInputType type,
                                     const gfx::Rect& caret_rect);
+  void OnMsgImeCompositionRangeChanged(const ui::Range& range);
   void OnMsgImeCancelComposition();
 
   void OnMsgDidActivateAcceleratedCompositing(bool activated);