Correctly handle promise rejections in the extension interface.

For DevTools extension commands, some of them were implemented
as async functions, but the message dispatcher wasn't changed
to also handle promise rejections, and thus any errors produced
were silently swallowed, instead of being reported to the caller
correctly.

Fixed: 327554073
Change-Id: If6701e5905b7bc3eecedd1f9f8b9e8ca50fe9352
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/7367453
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>

Author: bmeurer

front_end/panels/common/ExtensionServer.ts

@@ -1421,7 +1421,11 @@ export class ExtensionServer extends Common.ObjectWrapper.ObjectWrapper<EventTyp
     } else if (!this.extensionEnabled(port)) {
       result = this.status.E_FAILED('Permission denied');
     } else {
-      result = await handler(message, event.target as MessagePort);
+      try {
+        result = await handler(message, event.target as MessagePort);
+      } catch (e) {
+        result = this.status.E_FAILED(e.message);
+      }
     }
 
     if (result && message.requestId) {