Revert "Add diagnostic CHECKs for deserialization error."

This reverts commit c6f4b552.

Reason for revert: Remove diagnostic check.

Original change's description:
> Add diagnostic CHECKs for deserialization error.
>
> A crash has been traced back to a deserialization error on the
> viz.mojom.FrameSinkManager RegisterFrameSinkHierarchy IPC. Add some
> CHECKs to identify the root cause of bad FrameSinkId(s) being sent.
>
> Bug: 1115094
> Change-Id: Ie8aaf54bdddfb6d649b1386ac62edfb0df639cff
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2403581
> Reviewed-by: Jonathan Backer <backer@chromium.org>
> Commit-Queue: kylechar <kylechar@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#805836}

TBR=backer@chromium.org,kylechar@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1115094
Change-Id: I747cdb08bcb28fcd8e5f7cebee4c0d976c72c164
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2537578Reviewed-by: kylechar <kylechar@chromium.org>
Commit-Queue: kylechar <kylechar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827347}

components/viz/host/host_frame_sink_manager.cc

@@ -195,11 +195,6 @@ bool HostFrameSinkManager::RegisterFrameSinkHierarchy(
     return false;
   }
 
-  // TODO(crbug.com/1115094): Convert to DCHECKs after root cause of the
-  // deserialization error is identified.
-  CHECK(parent_frame_sink_id.is_valid()) << parent_frame_sink_id;
-  CHECK(child_frame_sink_id.is_valid()) << child_frame_sink_id;
-
   // Register and store the parent.
   frame_sink_manager_->RegisterFrameSinkHierarchy(parent_frame_sink_id,
                                                   child_frame_sink_id);