MD Settings People: Fix ChromeOS Change Picture Profile Icon tooltip

This fixes a regression where the tooltip to the profile picture is
never updated.

BUG=676782
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2622973002
Cr-Commit-Position: refs/heads/master@{#442755}

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

@@ -203,7 +203,7 @@ Polymer({
    */
   receiveProfileImage_: function(imageUrl, selected) {
     this.profileImageUrl_ = imageUrl;
-    this.$.profileImage.alt = this.i18n('profilePhoto');
+    this.$.profileImage.title = this.i18n('profilePhoto');
 
     if (!selected)
       return;