Revert "Initial implementation of Opaque Response Blocking (ORB)."

This reverts commit 8b9ef5d8.

Reason for revert: Causes URLLoaderTest crashes (https://crbug.com/1291026)

Original change's description:
> Initial implementation of Opaque Response Blocking (ORB).
>
> This CL implements most of the Opaque Response Blocking (ORB) algorithm
> from https://github.com/annevk/orb.  Major exceptions:
>
> 1) One of last steps in ORB asks to sniff the whole response body to
>    confirm whether the response contains valid Javascript.  ORB's
>    algorithm results in the most correct and secure behavior, but
>    requires more work to implement.  For now Chromium's implementation
>    determines `is_surely_not_javascript` by sniffing the first 1024
>    bytes with CORB's confirmation sniffers (see
>    IsSensitiveHtmlXmlOrJson).  This approximates ORB's behavior and
>    improves security (e.g. applying protection to HTML and XML served as
>    application/octet-stream), although unlike full ORB the current
>    implementation fails open rather than closed.
>
> 2) Chromium continues blocking responses by injecting an empty response
>    body and stripping HTTP headers (rather than by injecting a network
>    error).
>
> 3) Other differences are tracked in the "ORB v0.1 vs full ORB" section
>    of the doc here:
>    https://docs.google.com/document/d/1qUbE2ySi6av3arUEw5DNdFJIKKBbWGRGsXz_ew3S7HQ/edit#heading=h.mptmm5bpjtdn
>
> There are also some other minor differences that hopefully can be
> removed over time.
>
> Bug: 1178928, 1291026
> Change-Id: I4f018bdb75b5ff7d10233271e42476a9cc50bf2f
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3203018


> Reviewed-by: Charles Reis <creis@chromium.org>
> Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
> Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#963088}

Bug: 1178928
Change-Id: I3a60e5897a97c67848a868abd6e6e7328d0f1b11
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3416287
Auto-Submit: Sophey Dong <sophey@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Sophey Dong <sophey@chromium.org>
Owners-Override: Sophey Dong <sophey@chromium.org>
Cr-Commit-Position: refs/heads/main@{#963298}