[MD settings] content settings add site button; layout fixes

chrome/browser/resources/settings/settings_shared_css.html

 <link rel="import" href="chrome://resources/cr_elements/shared_style_css.html">
 <link rel="import" href="/settings_vars_css.html">
 
 <!-- Common styles for Material Design settings. -->
 <dom-module id="settings-shared">
   <template>
     <style include="cr-shared-style">
       button[is='paper-icon-button-light'] {
         -webkit-margin-end: -8px;  /* Allow ripple to overlap the end. */
         -webkit-margin-start: 16px;
@@ skipping 145 matching lines @@
         --paper-button: {
           font-weight: 500;
           text-align: start;
         };
       }
 
       /* See notes in .primary-button. */
       .secondary-button {
         --paper-button: {
           color: var(--paper-grey-600);
+          font-weight: 500;
+          min-width: 1em;  /* A tighter fit than 5.14em for short buttons. */

[dschuyler, 2016/10/19 18:56:42]

5.14em is the Polymer default value.

           text-decoration: none;
-          font-weight: 500;
         };
         --paper-button-flat-keyboard-focus: {
           background: rgba(0, 0, 0, .12);
         };
       }
 
       /* See notes in .primary-button. */
       .tertiary-button {
         --paper-button: {
           font-weight: 400;
@@ skipping 44 matching lines @@
 
       /* A list-frame is an outer container for list-items. It is intended to be
        * outside of a settings-box. A list-frame is likely to follow a
        * settings box. */
       .list-frame {
         @apply(--settings-list-frame-padding);
         align-items: center;
         display: block;
       }
 
-      .list-frame .secondary,
-      .list-item .secondary {
-        @apply(--settings-secondary);
-      }
-

[dschuyler, 2016/10/19 18:56:42]

These have become redundant.

       /* A list-item is intended to be contained within a list-frame. The list
        * frame will setup the initial start margin. */
       .list-item {
         align-items: center;
         display: flex;
         min-height: var(--settings-row-min-height);
         padding: 0;
       }
 
       /* A thin separator line under a list item. */
@@ skipping 70 matching lines @@
       /* 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);
       }
 
+      /* TODO(dschuyler): add :blank when it's supported by Chrome. */

[dschuyler, 2016/10/19 18:56:42]

The :blank thing looks awesome because it will not 
count blank space. The :empty does count blank space.
so <div></div> is empty and <div> </div> is not empty
(both of those are or will be :blank).

+      .secondary:empty {
+        margin: 0;
+      }
+
       /* The middle part (horizontally) of a row. */
       .settings-box .middle {
         -webkit-padding-start: 16px;
         align-items: center;
         flex: auto;
       }
 
       .settings-box .middle.two-line,
       .settings-box .start.two-line {
         display: flex;
@@ skipping 84 matching lines @@
       /* Turns the arrow direction downwards, when the bubble is placed above
        * the anchor element */
       .search-bubble-innards.above::after {
         -webkit-transform: rotate(-135deg);
         bottom: -5px;
         top: auto;
       }
     </style>
   </template>
 </dom-module>