[Resources] Add the Roboto font for contextual_search_promo_source and localize strings.

chrome/browser/search/contextual_search_promo_source.h

Index: chrome/browser/search/contextual_search_promo_source.h
diff --git a/chrome/browser/search/contextual_search_promo_source.h b/chrome/browser/search/contextual_search_promo_source.h
index 77100289c3bdf767cbff188227a8f6576d6c0a01..c8b362da821a62e84295168f1af6c8f03ded4df6 100644
--- a/chrome/browser/search/contextual_search_promo_source.h
+++ b/chrome/browser/search/contextual_search_promo_source.h
@@ -26,12 +26,17 @@ class ContextualSearchPromoSource : public content::URLDataSource {
   virtual std::string GetMimeType(
       const std::string& path_and_query) const OVERRIDE;
   virtual bool ShouldDenyXFrameOptions() const OVERRIDE;
+  virtual bool ShouldAddContentSecurityPolicy() const OVERRIDE;
 
   // Sends unmodified resource bytes.
   void SendResource(
       int resource_id,
       const content::URLDataSource::GotDataCallback& callback);
 
+  // Sends HTML with localized strings.
+  void SendHtmlWithStrings(
+    const content::URLDataSource::GotDataCallback& callback);
+
  private:
   DISALLOW_COPY_AND_ASSIGN(ContextualSearchPromoSource);
 };