Add a model for router and change

Also adds a change-service, which maintains the change model.

The new router model is maintained by gr-router, which will eventually
be moved and renamed to router-service.

Change-Id: I15fcf39d1de21dea975a687fb6efb6823d658c22
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts
index 26368ec..973ccc8 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts
@@ -25,7 +25,7 @@
 import {PolymerElement} from '@polymer/polymer/polymer-element';
 import {htmlTemplate} from './gr-change-list-view_html';
 import {page} from '../../../utils/page-wrapper-utils';
-import {GerritNav, GerritView} from '../../core/gr-navigation/gr-navigation';
+import {GerritNav} from '../../core/gr-navigation/gr-navigation';
 import {customElement, property} from '@polymer/decorators';
 import {AppElementParams} from '../../gr-app-types';
 import {
@@ -41,6 +41,7 @@
 import {ChangeListViewState} from '../../../types/types';
 import {fireTitleChange} from '../../../utils/event-util';
 import {appContext} from '../../../services/app-context';
+import {GerritView} from '../../../services/router/router-model';
 
 const LookupQueryPatterns = {
   CHANGE_ID: /^\s*i?[0-9a-f]{7,40}\s*$/i,
diff --git a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
index f3ed408..0a87503 100644
--- a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
@@ -29,7 +29,6 @@
 import {htmlTemplate} from './gr-dashboard-view_html';
 import {
   GerritNav,
-  GerritView,
   UserDashboard,
   YOUR_TURN,
 } from '../../core/gr-navigation/gr-navigation';
@@ -57,6 +56,7 @@
 import {ChangeStarToggleStarDetail} from '../../shared/gr-change-star/gr-change-star';
 import {DashboardViewState} from '../../../types/types';
 import {firePageError, fireTitleChange} from '../../../utils/event-util';
+import {GerritView} from '../../../services/router/router-model';
 
 const PROJECT_PLACEHOLDER_PATTERN = /\$\{project\}/g;
 
diff --git a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view_test.js b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view_test.js
index 1fa24ba..1f5d519 100644
--- a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view_test.js
+++ b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view_test.js
@@ -18,7 +18,8 @@
 import '../../../test/common-test-setup-karma.js';
 import './gr-dashboard-view.js';
 import {isHidden} from '../../../test/test-utils.js';
-import {GerritNav, GerritView} from '../../core/gr-navigation/gr-navigation.js';
+import {GerritNav} from '../../core/gr-navigation/gr-navigation.js';
+import {GerritView} from '../../../services/router/router-model.js';
 import {changeIsOpen} from '../../../utils/change-util.js';
 import {ChangeStatus} from '../../../constants/constants.js';
 import {createAccountWithId} from '../../../test/test-data-generators.js';