[NTP] Adds feature flags for NTP UI changes.

Bug: 837798, 837784, 839152
Change-Id: I7ab82dd70af2408cd57bae0e93b3175427af7470
Reviewed-on: https://chromium-review.googlesource.com/1040684
Reviewed-by: Ilya Sherman <[email protected]>
Commit-Queue: Ramya Nagarajan <[email protected]>
Cr-Commit-Position: refs/heads/master@{#555638}
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index a12e068..be7fe83f 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -1047,6 +1047,19 @@
     "Enable NTLMv2 HTTP Authentication. This disables NTLMv1 support.";
 #endif
 
+const char kNtpBackgroundsName[] = "New Tab Page Background Selection";
+const char kNtpBackgroundsDescription[] =
+    "Allow selection of a custom background image on the New Tab Page.";
+
+const char kNtpIconsName[] = "New Tab Page Custom Link Icons";
+const char kNtpIconsDescription[] =
+    "Show custom link icons on the New Tab Page, instead of Most Visited "
+    "tiles.";
+
+const char kNtpUIMdName[] = "New Tab Page Material Design UI";
+const char kNtpUIMdDescription[] =
+    "Updates the New Tab Page with Material Design elements.";
+
 const char kNumRasterThreadsName[] = "Number of raster threads";
 const char kNumRasterThreadsDescription[] =
     "Specify the number of raster threads.";