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

chrome/browser/instant/instant_loader.h

Index: chrome/browser/instant/instant_loader.h
diff --git a/chrome/browser/instant/instant_loader.h b/chrome/browser/instant/instant_loader.h
index 3837b87997eaadbe2a79ba4f47a75b88b2225371..4d595f60e224b805d4c8f5df91189f65eb65084f 100644
--- a/chrome/browser/instant/instant_loader.h
+++ b/chrome/browser/instant/instant_loader.h
@@ -20,6 +20,7 @@
 struct InstantAutocompleteResult;
 class InstantController;
 class TabContents;
+struct ThemeBackgroundInfo;
 
 namespace content {
 class NotificationDetails;
@@ -69,6 +70,12 @@ class InstantLoader : public content::NotificationObserver {
   void SendAutocompleteResults(
       const std::vector<InstantAutocompleteResult>& results);
 
+  // Tells the preview page about the current theme background.
+  void SendThemeBackgroundInfo(const ThemeBackgroundInfo& theme_info);
+
+  // Tells the preview page about the current theme area height.
+  void SendThemeAreaHeight(int height);
+
   // Tells the preview page that the user pressed the up or down key. |count|
   // is a repeat count, negative for moving up, positive for moving down.
   void OnUpOrDownKeyPressed(int count);