Auto resolve comment after applying fix

Google-Bug-Id: b/241899090
Release-Notes: skip
Change-Id: I2a48990274c6510d070eb19142a31258bc14b170

polygerrit-ui/app/elements/shared/gr-comment/gr-comment.ts

diff --git a/polygerrit-ui/app/elements/shared/gr-comment/gr-comment.ts b/polygerrit-ui/app/elements/shared/gr-comment/gr-comment.ts
index 1ac89d6..c844d42 100644
--- a/polygerrit-ui/app/elements/shared/gr-comment/gr-comment.ts
+++ b/polygerrit-ui/app/elements/shared/gr-comment/gr-comment.ts
@@ -1053,6 +1053,11 @@
           replacement
         ),
         patchNum: this.comment.patch_set,
+        onCloseFixPreviewCallbacks: [
+          fixApplied => {
+            if (fixApplied) this.handleAppliedFix();
+          },
+        ],
       };
     }
     if (isRobot(this.comment) && this.comment.fix_suggestions.length > 0) {
@@ -1065,6 +1070,7 @@
           };
         }),
         patchNum: this.comment.patch_set,
+        onCloseFixPreviewCallbacks: [],
       };
     }
     throw new Error('unable to create preview fix event');
@@ -1132,6 +1138,18 @@
     fire(this, 'reply-to-comment', eventDetail);
   }
 
+  private handleAppliedFix() {
+    const message = this.comment?.message;
+    assert(!!message, 'empty message');
+    const eventDetail: ReplyToCommentEventDetail = {
+      content: 'Fix applied.',
+      userWantsToEdit: false,
+      unresolved: false,
+    };
+    // Handled by <gr-comment-thread>.
+    fire(this, 'reply-to-comment', eventDetail);
+  }
+
   private async handleShowFix() {
     // Handled top-level in the diff and change view components.
     fire(this, 'open-fix-preview', await this.createFixPreview());