MD Settings: Add tooltip for Old Image in Change Picture.

chrome/browser/resources/settings/people_page/change_picture.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/util.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-a11y-keys/iron-a11y-keys.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-selector/iron-selector.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="/i18n_setup.html">
 <link rel="import" href="/icons.html">
@@ skipping 91 matching lines @@
               icon="settings:camera-alt" title="$i18n{takePhoto}"
               hidden="[[!cameraPresent_]]">
           </iron-icon>
           <iron-icon data-type$="[[selectionTypesEnum_.FILE]]"
               icon="settings:folder" title="$i18n{chooseFile}">
           </iron-icon>
           <img id="profileImage"
               data-type$="[[selectionTypesEnum_.PROFILE]]"
               src="[[profileImageUrl_]]" title="$i18n{profilePhotoLoading}">
           <img id="oldImage" data-type$="[[selectionTypesEnum_.OLD]]"
-              src="[[oldImageUrl_]]" hidden="[[!oldImageUrl_]]">
+              src="[[oldImageUrl_]]" hidden="[[!oldImageUrl_]]"
+              title="$i18n{oldPhoto}">
           <template is="dom-repeat" items="[[defaultImages_]]">
             <img data-type$="[[selectionTypesEnum_.DEFAULT]]"
                 data-default-image-index$="[[index]]" src="[[item.url]]"
                 title="[[item.title]]">
           </template>
         </iron-selector>
         <template is="dom-if" if="[[isAuthorCreditShown_(selectedItem_)]]">
           <div id="authorCredit">
             $i18n{authorCredit}
             [[getAuthorName_(selectedItem_, defaultImages_)]]
@@ skipping 16 matching lines @@
         </div>
         <settings-camera id="camera"
             camera-active="[[isCameraActive_(cameraPresent_, selectedItem_)]]"
             on-phototaken="onPhotoTaken_">
         </settings-camera>
       </div>
     </div>
   </template>
   <script src="change_picture.js"></script>
 </dom-module>