Delete some unused code found by -Wunused-function

chrome/browser/ui/webui/ntp/ntp_resource_cache.cc

Index: chrome/browser/ui/webui/ntp/ntp_resource_cache.cc
diff --git a/chrome/browser/ui/webui/ntp/ntp_resource_cache.cc b/chrome/browser/ui/webui/ntp/ntp_resource_cache.cc
index becc43fcfc4c21de33bbd2b46ebd6813e77121bc..40ba0360c08d9bad94bffc53794ffc2ac1932746 100644
--- a/chrome/browser/ui/webui/ntp/ntp_resource_cache.cc
+++ b/chrome/browser/ui/webui/ntp/ntp_resource_cache.cc
@@ -173,13 +173,6 @@ std::string GetNewTabBackgroundTilingCSS(
   return ThemeService::TilingToString(repeat_mode);
 }
 
-// Is the current time within a given date range?
-bool InDateRange(double begin, double end) {
-  Time start_time = Time::FromDoubleT(begin);
-  Time end_time = Time::FromDoubleT(end);
-  return start_time < Time::Now() && end_time > Time::Now();
-}
-
 }  // namespace
 
 NTPResourceCache::NTPResourceCache(Profile* profile)