[MD settings] flag to enable site settings All sites and Site details pages

chrome/browser/resources/settings/settings_shared_css.html

Index: chrome/browser/resources/settings/settings_shared_css.html
diff --git a/chrome/browser/resources/settings/settings_shared_css.html b/chrome/browser/resources/settings/settings_shared_css.html
index 371b8a391af30bbbcddd9c02d6b6af47574ebd60..af3e621614f2b2d354b05e9a2e377b0c6ec29a9e 100644
--- a/chrome/browser/resources/settings/settings_shared_css.html
+++ b/chrome/browser/resources/settings/settings_shared_css.html
@@ -317,6 +317,13 @@
         justify-content: center;
       }
 
+      /*
+       * A settings-box with no height other than the seprator line.
+       */
+      .settings-box.line-only {
+        min-height: 0;
+      }
+
       /* The lower line of text in a two-line row. */
       .secondary {
         @apply(--settings-secondary);