[MD Settings] Fixed accessibility issues in password section.

Specify labels that are referenced using the aria-labelledby attribute to passwords section's searchInputs and passwords. Remove the for attribute, not needed since we are using aria-labelledby instead.

Bug: 737739
Change-Id: Ibdc7d0752d2e1972c8692ca743e39ababc24f868
Reviewed-on: https://chromium-review.googlesource.com/568240Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Tina Quach <quacht@google.com>
Cr-Commit-Position: refs/heads/master@{#487530}

chrome/browser/resources/settings/passwords_and_forms_page/password_list_item.html

@@ -33,9 +33,9 @@
       <div class="password-column">
         <template is="dom-if" if="[[!item.federationText]]">
           <!-- Password type and disabled in order to match mock. -->
-          <input id="password" type="password" class="password-field text-elide"
-               disabled value=
-               "[[getEmptyPassword_(item.numCharactersInPassword)]]">
+          <input id="password" aria-label=$i18n{editPasswordPasswordLabel}
+              type="password" class="password-field text-elide" disabled
+              value="[[getEmptyPassword_(item.numCharactersInPassword)]]">
           </input>
         </template>
         <template is="dom-if" if="[[item.federationText]]">

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

@@ -72,7 +72,7 @@
     <iron-icon id="searchIcon" icon="cr:search"></iron-icon>
     <paper-input-container no-label-float>
       <input id="searchInput" type="search" on-search="onSearchTermSearch"
-          on-input="onSearchTermInput" aria-labelledby="prompt" incremental
+          on-input="onSearchTermInput" aria-label$="[[label]]" incremental
           autofocus$="[[autofocus]]" placeholder="[[label]]">
       <button suffix is="paper-icon-button-light" id="clearSearch"
           class="icon-cancel" on-tap="onTapClear_" title="[[clearLabel]]"

ui/webui/resources/cr_elements/cr_toolbar/cr_toolbar_search_field.html

@@ -142,6 +142,7 @@
     <div id="searchTerm">
       <label id="prompt" for="searchInput" aria-hidden="true">[[label]]</label>
       <input id="searchInput"
+          aria-labelledby="prompt"
           type="search"
           on-input="onSearchTermInput"
           on-search="onSearchTermSearch"