alternate ntp: implement searchbox api for instant overlay to adopt themes

chrome/renderer/searchbox/searchbox.h

Index: chrome/renderer/searchbox/searchbox.h
diff --git a/chrome/renderer/searchbox/searchbox.h b/chrome/renderer/searchbox/searchbox.h
index 10b3b22d1f22f83f1ac6235a4b7c679398e18ee2..d6e561ceb7f033fa947a80e3e3fab08daf7891fd 100644
--- a/chrome/renderer/searchbox/searchbox.h
+++ b/chrome/renderer/searchbox/searchbox.h
@@ -49,6 +49,8 @@ class SearchBox : public content::RenderViewObserver,
   // Searchbox retains ownership of this object.
   const InstantAutocompleteResult*
       GetAutocompleteResultWithId(size_t restricted_id) const;
+  const ThemeBackgroundInfo& GetThemeBackgroundInfo();
+  int GetThemeAreaHeight();
 
  private:
   // RenderViewObserver implementation.
@@ -68,6 +70,8 @@ class SearchBox : public content::RenderViewObserver,
   void OnFocus();
   void OnBlur();
   void OnActiveTabModeChanged(bool active_tab_is_ntp);
+  void OnThemeChanged(const ThemeBackgroundInfo& theme_info);
+  void OnThemeAreaHeightChanged(int height);
 
   // Sets the searchbox values to their initial value.
   void Reset();
@@ -83,6 +87,8 @@ class SearchBox : public content::RenderViewObserver,
   std::vector<InstantAutocompleteResult> last_autocomplete_results_;
   bool is_focused_;
   bool active_tab_is_ntp_;
+  ThemeBackgroundInfo theme_info_;
+  int theme_area_height_;
 
   DISALLOW_COPY_AND_ASSIGN(SearchBox);
 };