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

content/browser/renderer_host/render_widget_host_view.h

Index: content/browser/renderer_host/render_widget_host_view.h
diff --git a/content/browser/renderer_host/render_widget_host_view.h b/content/browser/renderer_host/render_widget_host_view.h
index fa0d39aadcf815e000c5331f14e5abb66616e5d4..60a4a4d1e37e6c5eea2f787ec123fbd151a8a94e 100644
--- a/content/browser/renderer_host/render_widget_host_view.h
+++ b/content/browser/renderer_host/render_widget_host_view.h
@@ -135,6 +135,9 @@ class RenderWidgetHostView {
   // Cancel the ongoing composition of the input method attached to the view.
   virtual void ImeCancelComposition() = 0;
 
+  // Updates the range of the marked text in an IME composition.
+  virtual void ImeCompositionRangeChanged(int start, int end) {}
+
   // Informs the view that a portion of the widget's backing store was scrolled
   // and/or painted.  The view should ensure this gets copied to the screen.
   //
@@ -172,7 +175,7 @@ class RenderWidgetHostView {
   virtual void SetTooltipText(const std::wstring& tooltip_text) = 0;
 
   // Notifies the View that the renderer text selection has changed.
-  virtual void SelectionChanged(const std::string& text) {}
+  virtual void SelectionChanged(const std::string& text, int start, int end) {}
 
   // Tells the View whether the context menu is showing. This is used on Linux
   // to suppress updates to webkit focus for the duration of the show.