Log why PrintRenderFrameHelper::SnapshotForContentAnalysis() failed

Emit log messages on failure to help make debugging easier.

Change-Id: I8af8266ead23560ceb87490aa831a5d0de2db515
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4350971


Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Alan Screen <awscreen@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1118947}