Revert "Re-enable RendererSideContentDecoding for Navigations and SXG"

This reverts commit 468d896aa9ff99143bc4da03bfab116c360bebc1.

Reason for revert:DownloadContentTest.CompressedResponseWithContentDispositionInsufficientResources failure on multiple bots

List of failed builders:

Builder: linux-chromeos-chrome
https://ci.chromium.org/p/chrome/builders/ci/linux-chromeos-chrome
First failing build:
https://ci.chromium.org/p/chrome/builders/ci/linux-chromeos-chrome/b8718844112705093041
Step "content_browsertests (retry shards) on Ubuntu-22.04 or Ubuntu-20.04" failing on builder "chromium/ci/fuchsia-arm64-cast-receiver-rel"

Builder: fuchsia-arm64-cast-receiver-rel
https://ci.chromium.org/p/chromium/builders/ci/fuchsia-arm64-cast-receiver-rel
First failing build:
https://ci.chromium.org/p/chromium/builders/ci/fuchsia-arm64-cast-receiver-rel/b8718845082436844721
Step "content_browsertests (retry shards) on Ubuntu-22.04" failing on builder "chromium/ci/fuchsia-x64-cast-receiver-rel"

Builder: fuchsia-x64-cast-receiver-rel
https://ci.chromium.org/p/chromium/builders/ci/fuchsia-x64-cast-receiver-rel
First failing build:
https://ci.chromium.org/p/chromium/builders/ci/fuchsia-x64-cast-receiver-rel/b8718843408303503537


Original change's description:
> Re-enable RendererSideContentDecoding for Navigations and SXG
>
> This CL re-enables the `RendererSideContentDecoding` feature for
> navigation requests and for Signed Exchanges (SXG) loadings.
>
> Previously, this feature was disabled for these requests [1][2] because
> responses ultimately consumed by the browser process require decoded
> content, but the feature caused the network service to skip decoding.
> This impacted:
> - Downloads triggered by `Content-Disposition: attachment`.
> - Signed Exchanges (SXG), where the outer response's encoded payload
>   must be decoded before parsing can occur in the browser process.
>
> This change introduces a unified solution using a new
> `ContentDecodingInterceptor` mechanism to correctly handle these cases
> while allowing standard navigations to potentially benefit from
> client-side (renderer) decoding:
>
> 1.  The `client_side_content_decoding_enabled` flag is set again in
>     `CreateResourceRequestForNavigation` when the feature flag is
>     enabled.
> 2.  The network service (`URLRequestHttpJob`) now consistently skips
>     decoding if this flag is set, regardless of content type (the
>     previous SXG exception is removed). It reports the skipped encoding
>     types via `URLResponseHead::client_side_content_decoding_types`.
> 3.  A new Mojo IPC, `NetworkService::InterceptUrlLoaderForBodyDecoding`,
>     and a browser-side helper,
>     `ContentDecodingInterceptor::InterceptOnNetworkService`, are added.
>     These allow the browser process to request the network service to
>     insert a decoding interceptor on demand.
> 4.  Crucially, both `NavigationRequest` (before checking for downloads)
>     and `SignedExchangeLoader` (before processing the SXG response) now
>     check if `client_side_content_decoding_types` is populated. If
>     decoding was skipped by the network service, they call
>     `InterceptOnNetworkService`. This ensures a decoding step, performed
>     within the network service process, is inserted before the body
>     reaches the download manager or the SXG parsing logic.
>
> This approach allows standard navigation responses destined for a
> renderer to bypass network service decoding (if the feature is enabled),
> while guaranteeing that downloads and SXG outer responses are correctly
> decoded before being consumed by browser-process logic.
>
> This CL also add a new `switch (reason)` case in the
> ConvertInterruptReasonToMojoNetworkRequestStatus() method to handle the
> mojo data pipe creation error case correctly. This case is tested by the
> new test CompressedResponseWithContentDispositionInsufficientResources
> in DownloadContentTest.
>
> [1]: https://crrev.com/c/6399553
> [2]: https://crrev.com/c/6399234
>
>
> Bug: 391950057
> Fixed: 406877444
> Change-Id: I9535db61464dfd0fd3c8e128affa7aa4ac6c3fc2
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6399776
> Reviewed-by: Adam Rice <ricea@chromium.org>
> Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
> Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
> Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
> Reviewed-by: Min Qin <qinmin@chromium.org>
> Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1440565}

Bug: 391950057
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: I87e46de67bcbad0b0e656e3f58bc81c747a13784
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6420243
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Owners-Override: Mikihito Matsuura <mikt@google.com>
Commit-Queue: Mikihito Matsuura <mikt@google.com>
Cr-Commit-Position: refs/heads/main@{#1440677}