[M149] Validate CGImage dimensions in MouseCursorMonitorMac

Original change's description:
> Validate CGImage dimensions in MouseCursorMonitorMac
>
> This adds missing height checks alongside the existing width checks
> when processing and scaling the cursor image.
>
> Fixed: chromium:513268100
> Change-Id: Ida1e58334a9d3bda429819e4af51b33afbd0a95d
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/472700
> Reviewed-by: Alexander Cooper <alcooper@chromium.org>
> Auto-Submit: Johannes Kron <kron@webrtc.org>
> Commit-Queue: Alexander Cooper <alcooper@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#47715}

(cherry picked from commit b343cd4e280980f26b4feb80684f57d5b4324e12)

Bug: chromium:514928856,chromium:513268100
Change-Id: Ida1e58334a9d3bda429819e4af51b33afbd0a95d
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/473981
Auto-Submit: Chrome Cherry Picker <chrome-cherry-picker@chops-service-accounts.iam.gserviceaccount.com>
Bot-Commit: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/7827@{#1}
Cr-Branched-From: d606bc991592fbf4dcbe85e9d05db5e501a5ad42-refs/heads/main@{#47595}