Remove some unneeded default_avatar complexity

We only need it in a single place, but were previously passing
from backend via a bunch of constructors then eventually assigning

app/assets/javascripts/boards/index.js

@@ -84,7 +84,6 @@ export default () => {
       rootPath: $boardApp.dataset.rootPath,
       bulkUpdatePath: $boardApp.dataset.bulkUpdatePath,
       detailIssue: boardsStore.detail,
-      defaultAvatar: $boardApp.dataset.defaultAvatar,
     },
     computed: {
       detailIssueVisible() {
@@ -129,13 +128,10 @@ export default () => {
               position = -1;
             }
 
-            boardsStore.addList(
-              {
+            boardsStore.addList({
               ...listObj,
               position,
-              },
-              this.defaultAvatar,
-            );
+            });
           });
 
           boardsStore.addBlankState();

app/assets/javascripts/boards/models/assignee.js

 export default class ListAssignee {
-  constructor(obj, defaultAvatar) {
+  constructor(obj) {
     this.id = obj.id;
     this.name = obj.name;
     this.username = obj.username;
-    this.avatar = obj.avatar_url || obj.avatar || defaultAvatar;
+    this.avatar = obj.avatar_url || obj.avatar || gon.default_avatar_url;
     this.path = obj.path;
     this.state = obj.state;
     this.webUrl = obj.web_url || obj.webUrl;

app/assets/javascripts/boards/models/issue.js

@@ -10,7 +10,7 @@ import IssueProject from './project';
 import boardsStore from '../stores/boards_store';
 
 class ListIssue {
-  constructor(obj, defaultAvatar) {
+  constructor(obj) {
     this.subscribed = obj.subscribed;
     this.labels = [];
     this.assignees = [];
@@ -22,11 +22,11 @@ class ListIssue {
     this.closed = obj.closed;
     this.isLoading = {};
 
-    this.refreshData(obj, defaultAvatar);
+    this.refreshData(obj);
   }
 
-  refreshData(obj, defaultAvatar) {
-    boardsStore.refreshIssueData(this, obj, defaultAvatar);
+  refreshData(obj) {
+    boardsStore.refreshIssueData(this, obj);
   }
 
   addLabel(label) {

app/assets/javascripts/boards/models/list.js

@@ -36,7 +36,7 @@ const TYPES = {
 };
 
 class List {
-  constructor(obj, defaultAvatar) {
+  constructor(obj) {
     this.id = obj.id;
     this._uid = this.guid();
     this.position = obj.position;
@@ -55,7 +55,6 @@ class List {
     this.maxIssueCount = Object.hasOwnProperty.call(obj, 'max_issue_count')
       ? obj.max_issue_count
       : 0;
-    this.defaultAvatar = defaultAvatar;
 
     if (obj.label) {
       this.label = new ListLabel(obj.label);
@@ -156,7 +155,7 @@ class List {
 
   createIssues(data) {
     data.forEach(issueObj => {
-      this.addIssue(new ListIssue(issueObj, this.defaultAvatar));
+      this.addIssue(new ListIssue(issueObj));
     });
   }
 

app/assets/javascripts/boards/stores/boards_store.js

@@ -66,8 +66,8 @@ const boardsStore = {
   showPage(page) {
     this.state.currentPage = page;
   },
-  addList(listObj, defaultAvatar) {
-    const list = new List(listObj, defaultAvatar);
+  addList(listObj) {
+    const list = new List(listObj);
     this.state.lists = _.sortBy([...this.state.lists, list], 'position');
 
     return list;
@@ -598,7 +598,7 @@ const boardsStore = {
   clearMultiSelect() {
     this.multiSelect.list = [];
   },
-  refreshIssueData(issue, obj, defaultAvatar) {
+  refreshIssueData(issue, obj) {
     issue.id = obj.id;
     issue.iid = obj.iid;
     issue.title = obj.title;
@@ -627,7 +627,7 @@ const boardsStore = {
     }
 
     if (obj.assignees) {
-      issue.assignees = obj.assignees.map(a => new ListAssignee(a, defaultAvatar));
+      issue.assignees = obj.assignees.map(a => new ListAssignee(a));
     }
   },
 };

app/helpers/boards_helper.rb

@@ -14,7 +14,6 @@ module BoardsHelper
       issue_link_base: build_issue_link_base,
       root_path: root_path,
       bulk_update_path: @bulk_issues_path,
-      default_avatar: image_path(default_avatar),
       time_tracking_limit_to_hours: Gitlab::CurrentSettings.time_tracking_limit_to_hours.to_s,
       recent_boards_endpoint: recent_boards_path
     }

ee/app/assets/javascripts/boards/models/issue.js

@@ -2,8 +2,8 @@ import ListIssue from '~/boards/models/issue';
 import IssueProject from '~/boards/models/project';
 
 class ListIssueEE extends ListIssue {
-  constructor(obj, defaultAvatar) {
-    super(obj, defaultAvatar, {
+  constructor(obj) {
+    super(obj, {
       IssueProject,
     });
 

spec/frontend/boards/issue_card_spec.js

@@ -155,18 +155,17 @@ describe('Issue card component', () => {
 
     describe('assignee default avatar', () => {
       beforeEach(done => {
+        global.gon.default_avatar_url = 'default_avatar';
+
         wrapper.setProps({
           issue: {
             ...wrapper.props('issue'),
             assignees: [
-              new ListAssignee(
-                {
+              new ListAssignee({
                 id: 1,
                 name: 'testing 123',
                 username: 'test',
-                },
-                'default_avatar',
-              ),
+              }),
             ],
           },
         });
@@ -174,6 +173,10 @@ describe('Issue card component', () => {
         wrapper.vm.$nextTick(done);
       });
 
+      afterEach(() => {
+        global.gon.default_avatar_url = null;
+      });
+
       it('displays defaults avatar if users avatar is null', () => {
         expect(wrapper.find('.board-card-assignee img').exists()).toBe(true);
         expect(wrapper.find('.board-card-assignee img').attributes('src')).toBe(