Third-party doodles: Add an about:flags entry for testing

Bug: 752453
Change-Id: I597070d6d98d1e6bc0d14c9c9a970261d171a95b
Reviewed-on: https://chromium-review.googlesource.com/618711
Commit-Queue: Marc Treib <[email protected]>
Reviewed-by: Maria Khomenko <[email protected]>
Reviewed-by: Bernhard Bauer <[email protected]>
Cr-Commit-Position: refs/heads/master@{#496668}
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 97a83d0..7cfca13 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -1928,6 +1928,12 @@
 const char kUseDdljsonApiDescription[] =
     "Enables the new ddljson API to fetch Doodles for the NTP.";
 
+const char kThirdPartyDoodlesName[] =
+    "Enable Doodles for third-party search engines";
+const char kThirdPartyDoodlesDescription[] =
+    "Enables fetching and displaying Doodles on the NTP for third-party search "
+    "engines.";
+
 const char kXGEOVisibleNetworksName[] = "Enable XGEO Visible Networks";
 const char kXGEOVisibleNetworksDescription[] =
     "If location permissions are granted, include visible networks in the XGEO "