Await plugin load before auto-opening revert dialog

The `?revert` query parameter will automatically open the revert dialog
when the change view loads, but would sometimes do so before plugins had
a chance to bind listeners for the revert event. With this change, the
revert dialog is not automatically opened until all plugins have loaded.

Bug: Issue 5189
Change-Id: Id731c2d140e01236175142ea9d3b88d53e3c4709

polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.js

@@ -445,15 +445,18 @@
     },
 
     _maybeShowRevertDialog: function() {
-      this._getLoggedIn().then(function(loggedIn) {
+      Gerrit.awaitPluginsLoaded()
-        if (!loggedIn || this._change.status !== this.ChangeStatus.MERGED) {
+        .then(this._getLoggedIn.bind(this))
-          // Do not display dialog if not logged-in or the change is not merged.
+        .then(function(loggedIn) {
-          return;
+          if (!loggedIn || this._change.status !== this.ChangeStatus.MERGED) {
-        }
+            // Do not display dialog if not logged-in or the change is not
-        if (!!this._getUrlParameter('revert')) {
+            // merged.
-          this.$.actions.showRevertDialog();
+            return;
-        }
+          }
-      }.bind(this));
+          if (!!this._getUrlParameter('revert')) {
+            this.$.actions.showRevertDialog();
+          }
+        }.bind(this));
     },
 
     _maybeShowReplyDialog: function() {

polygerrit-ui/app/elements/change/gr-change-view/gr-change-view_test.html

@@ -612,6 +612,9 @@ limitations under the License.
       sandbox.stub(element.$.restAPI, 'getLoggedIn', function() {
         return Promise.resolve(true);
       });
+      sandbox.stub(Gerrit, 'awaitPluginsLoaded', function() {
+        return Promise.resolve();
+      });
 
       element._patchRange = {
         basePatchNum: 'PARENT',
@@ -638,6 +641,7 @@ limitations under the License.
           done);
 
       element._maybeShowRevertDialog();
+      assert.isTrue(Gerrit.awaitPluginsLoaded.called);
     });
 
     suite('scroll related tests', function() {