Emit signed-exchange error message from the frame that generates it

This error message is mistakenly emitted from the root frame. This
causes error messages from a chrome-untrusted:// iframe to be emitted as
if they are from the containing chrome://. These errors are then
reported to the crash reporting server, which is supposed to collect
only chrome:// errors.

Fixed: 40070758, 399764212
Change-Id: Ifc6f10821209ec450ae42b1514a790f46624d5d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6426289
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Commit-Queue: Keren Zhu <kerenzhu@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1442239}