This reverts commit d9fbfeb8.

Reason for revert: see bug.
Bug: 906847

Original change's description:
> inspector: return [[StableObjectId]] as internal property
> 
> This property might be useful for fast '===' check.
> 
> R=​dgozman@chromium.org,yangguo@chromium.org
> 
> Bug: none
> Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel
> Change-Id: Iabc3555ce1ec2c14cf0ccd40b7d964ae144e7352
> Reviewed-on: https://chromium-review.googlesource.com/1226411
> Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56095}

TBR=dgozman@chromium.org,yangguo@chromium.org,kozyatinskiy@chromium.org,jgruber@chromium.org

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

Bug: none
Change-Id: I68c700b7b8fd0a015f099460c15665d74e4da183
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel
Reviewed-on: https://chromium-review.googlesource.com/c/1363558Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Alexei Filippov <alph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58077}