MD Settings: Introduce CrScrollableBehavior

chrome/browser/resources/settings/settings_vars_css.html

Index: chrome/browser/resources/settings/settings_vars_css.html
diff --git a/chrome/browser/resources/settings/settings_vars_css.html b/chrome/browser/resources/settings/settings_vars_css.html
index 5621d022acf04aa4c3406a3b29a3a65588187788..87b0d83c54e29617055862a35940add057f48677 100644
--- a/chrome/browser/resources/settings/settings_vars_css.html
+++ b/chrome/browser/resources/settings/settings_vars_css.html
@@ -35,6 +35,13 @@
     };
     --settings-error-color: var(--paper-red-700);
 
+    --settings-list-frame-padding: {
+      -webkit-padding-end: 20px;
+      -webkit-padding-start: 56px;
+      padding-bottom: 0;
+      padding-top: 0;
+    }
+
     /* Some colors use non-MD colors.  These custom colors are specified by
      * UX design (bettes@). */
     --settings-nav-grey: rgb(90, 90, 90);