[NTP Cleanup] Hide customize button if window is too short.

Bug: 959097
Change-Id: Ie251657ed6687846ff7284223b3ce541ae958e32
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1643988
Commit-Queue: Gayane Petrosyan <gayane@chromium.org>
Reviewed-by: Kyle Milka <kmilka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#666354}

chrome/browser/resources/local_ntp/customize.css

@@ -107,6 +107,15 @@ html[darkmode=true] .ep-enhanced #edit-bg-text {
   }
 }
 
+/* If window height is less then the customization menu height, then hide the
+ * 'customize' button.
+ */
+@media (max-height: 528px) {
+  #edit-bg {
+    display: none;
+  }
+}
+
 #edit-bg-dialog::backdrop {
   background: transparent;
 }