Disable HTML close button in Reader Mode

components/dom_distiller/core/css/distilledpage.css

Index: components/dom_distiller/core/css/distilledpage.css
diff --git a/components/dom_distiller/core/css/distilledpage.css b/components/dom_distiller/core/css/distilledpage.css
index 80dc711f775fa8c196cfeee473536cd707db7177..4c01939fd14ea0f136d2cd34e20db16828e0eea8 100644
--- a/components/dom_distiller/core/css/distilledpage.css
+++ b/components/dom_distiller/core/css/distilledpage.css
@@ -256,6 +256,11 @@ h6 {
 }
 
 #closeReaderView {
+  /*
+  TODO(mdjones): Remove the "display: none;" style when the Reader Mode bar
+                 behaves like the toolbar when scrolling.
+  */
+  display: none;
   flex: 0 0 auto;
   font-family: 'Roboto', sans-serif;
   font-weight: 700;