[MD settings] remove label float from dropdowns so that they center c…

…orrectly

This CL adds the no-label-float property to dropdowns without a label so
that they center correctly vertically.

BUG=632543
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2191203002
Cr-Commit-Position: refs/heads/master@{#408696}

chrome/browser/resources/settings/search_page/search_page.html

@@ -19,7 +19,7 @@
       <neon-animatable id="main">
         <div class="settings-box first">
           <p class="start">$i18n{searchExplanation}</p>
-          <paper-dropdown-menu vertical-align="auto">
+          <paper-dropdown-menu vertical-align="auto" no-label-float>
             <paper-listbox class="dropdown-content"
                 selected="[[getSelectedSearchEngineIndex_(searchEngines_)]]"
                 on-iron-select="onIronSelect_">

chrome/browser/resources/settings/site_settings/media_picker.html

@@ -11,7 +11,7 @@
       }
     </style>
     <div class="settings-box" id="picker" hidden>
-      <paper-dropdown-menu vertical-align="auto">
+      <paper-dropdown-menu vertical-align="auto" no-label-float>
         <paper-listbox id="mediaPicker" class="dropdown-content"
             attr-for-selected="media-picker-value"
             on-iron-activate="onMediaPickerActivate_">

chrome/browser/resources/settings/site_settings/site_data_details_dialog.html

@@ -18,7 +18,7 @@
       <div class="body">
         <div class="layout horizontal" id="container">
           <div class="flex">
-            <paper-dropdown-menu vertical-align="auto">
+            <paper-dropdown-menu vertical-align="auto" no-label-float>
               <paper-listbox id="picker" class="dropdown-content"
                   attr-for-selected="picker-value"
                   on-iron-activate="onItemSelected_">