MD Settings, cleanup: Remove obsolete references to paper-dialog, paper-item.

chrome/browser/resources/settings/settings_vars_css.html

 <link rel="import" href="chrome://resources/cr_elements/shared_vars_css.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-styles/color.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-styles/default-theme.html">
 
 <!-- Common css variables for Material Design settings. -->
 <style is="custom-style">
   /* We keep our vars in sort order, though some vars must be defined prior to
    * others. The --settings-* vars are defined explicitly prior to the --paper-*
    * and --iron-* vars.
    */
@@ skipping 76 matching lines @@
     /* Spacing between a control (e.g. checkbox) and its label. */
     --settings-control-label-spacing: 20px;
 
     /* Spacing between policy (controlledBy) indicator and control. */
     --settings-controlled-by-spacing: var(--cr-controlled-by-spacing);
 
     --iron-icon-fill-color: var(--paper-grey-600);
     --iron-icon-height: var(--cr-icon-size);
     --iron-icon-width: var(--cr-icon-size);
     --paper-checkbox-label-color: inherit;
-    --paper-dialog-color: inherit;
 
     --paper-icon-button: {
       /**
        * This makes the icons 20px (in combination with --cr-icon-ripple-size),
        * since paper-icon-button>iron-icon width and height are hard-coded to
        * 100%.
        */
       padding: var(--cr-icon-ripple-padding);
     };
     --paper-input-container-focus-color: var(--google-blue-500);
@@ skipping 36 matching lines @@
     --paper-toggle-button-unchecked-button: var(--settings-toggle-button-size);
     --paper-toggle-button-unchecked-ink: var(--settings-toggle-ink-size);
 
     --settings-input-underline: {
       border-color: var(--paper-grey-300);
     };
 
     --paper-input-container-underline: var(--settings-input-underline);
   }
 </style>