MD Settings: Fix several global UI polish bugs.

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 81706049f5073dddc05e9ca02a3c40858c5f7b6d..441b26ab90d60399be395b53387a4c4c102cf4d7 100644
--- a/chrome/browser/resources/settings/settings_shared_css.html
+++ b/chrome/browser/resources/settings/settings_shared_css.html
@@ -40,6 +40,7 @@
       paper-button {
         height: 32px;
         margin: 0;
+        border-radius: 4px;
       }
 
       paper-button[toggles][active] {
@@ -253,6 +254,10 @@
         min-height: var(--settings-box-two-line-min-height);
       }
 
+      .settings-box.three-line {
+        min-height: var(--settings-box-three-line-min-height);
+      }
+
       /* We use an explicit tag to remove the top border, rather than a
        * :first-of-type modifier. This is a conscious choice, please consult
        * with dbeam@ or dschuyler@ prior to changing it. */