[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..ac07ddc534e076e18169b93844941aac003c483e 100644
--- a/chrome/browser/resources/settings/settings_shared_css.html
+++ b/chrome/browser/resources/settings/settings_shared_css.html
@@ -307,16 +307,18 @@
         min-height: var(--settings-row-two-line-min-height);
       }
 
-      /*
-       * A single start-aligned column, generally but not necessarily used in
-       * combination with two-line.
-       */
+      /* A start-aligned column. */
       .single-column {
         align-items: flex-start;
         flex-direction: column;
         justify-content: center;
       }
 
+      /* A settings-box with no height other than the separator line. */
+      .settings-box.line-only {
+        min-height: 0;
+      }
+
       /* The lower line of text in a two-line row. */
       .secondary {
         @apply(--settings-secondary);