MD Settings: Fix several global UI polish bugs.

chrome/browser/resources/settings/settings_page/settings_subpage.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-resizable-behavior/iron-resizable-behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/neon-animation/neon-animatable-behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="/icons.html">
 <link rel="import" href="/route.html">
 <link rel="import" href="/settings_page/settings_subpage_search.html">
 <link rel="import" href="/settings_shared_css.html">
 
 <dom-module id="settings-subpage">
   <template>
     <style include="settings-shared">
       :host {
         --iron-icon-fill-color: var(--settings-nav-grey);
         display: block;
         padding-bottom: 60px;
       }
 
       .settings-box.first {
         min-height: 40px;
+        padding-bottom: 24px;

[dschuyler, 2017/01/28 02:24:26]

It may be an optical illusion, but the screen shot of this padding looks much
larger than in Alan's reference screen shot. I'm wondering if Alan meant from
the bottom of one line of text to the top of the other line of text should be
24px (that's the way the mock have often shown spacing). Because the text lines
themselves may have space above/below them, the 24px may need to be a smaller
value to get the same visual result (or the other spacing needs to be removed).

[scottchen, 2017/01/30 22:39:28]

I think I misunderstood the bug report for this one.

         padding-top: 8px;
       }
 
+      .settings-box.first > h1 {
+        -webkit-margin-start: 4px;
+      }
+
       paper-icon-button {
         /* Centers the ripple on the icon with appropriate margin on right. */
         -webkit-margin-end: 8px;
         -webkit-margin-start: -8px;
       }
 
       h1 {
         color: var(--settings-nav-grey);
         flex: 1;  /* Push other items to the end. */
         font-size: 107.6923%;  /* Go to 14px from 13px */
@@ skipping 13 matching lines @@
         <settings-subpage-search label="[[searchLabel]]"
             on-search-changed="onSearchChanged_">
         </settings-subpage-search>
       </template>
       <content select=".subpage-title-extra"></content>
     </div>
     <content></content>
   </template>
   <script src="settings_subpage.js"></script>
 </dom-module>