Whitelist themes in CSP of chrome://newtab

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

Index: chrome/browser/ui/webui/ntp/new_tab_ui.cc
diff --git a/chrome/browser/ui/webui/ntp/new_tab_ui.cc b/chrome/browser/ui/webui/ntp/new_tab_ui.cc
index a9812b4e0d2724d6d5d5ff909083a5121ba17172..229dd3c3424a888f304039226df874991da450c4 100644
--- a/chrome/browser/ui/webui/ntp/new_tab_ui.cc
+++ b/chrome/browser/ui/webui/ntp/new_tab_ui.cc
@@ -242,7 +242,8 @@ std::string NewTabUI::NewTabHTMLSource::GetContentSecurityPolicyStyleSrc()
 
 std::string NewTabUI::NewTabHTMLSource::GetContentSecurityPolicyImgSrc()
     const {
-  return "img-src chrome-search://thumb chrome-search://thumb2 data:;";
+  return "img-src chrome-search://thumb chrome-search://thumb2 "
+      "chrome-search://theme chrome://theme data:;";
 }
 
 std::string NewTabUI::NewTabHTMLSource::GetContentSecurityPolicyChildSrc()