Add a policy to hide the Web Store on new tabs.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 0bb8a77abefce682e6a11a5e597f9c5a04410590..c408c4edf6cfa4397d31fac4d4b627730af17741 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -528,6 +528,10 @@ const char kNetworkPredictionEnabled[] = "dns_prefetching.enabled";
 // See possible values in external_provider_impl.cc.
 const char kDefaultAppsInstallState[] = "default_apps_install_state";
 
+// A boolean pref set to true if the Chrome Web Store icons should be hidden
+// from the New Tab Page.
+const char kHideWebStoreIcon[] = "hide_web_store_icon";
+
 #if defined(OS_CHROMEOS)
 // An integer pref to initially mute volume if 1. This pref is ignored if
 // |kAudioOutputAllowed| is set to false, but its value is preserved, therefore