This reverts commit e416c92a.

Reason for revert: Reverted parent:
https://chromium-review.googlesource.com/c/angle/angle/+/2481612

Original change's description:
> Vulkan: Fold deferred clears into current clears
>
> If there are clears prior to a glClear() call, those clears were
> flushed (starting a new render pass) and then the clear call's clears
> would be applied (essentially modifying the loadOps of said render
> pass).
>
> The main downside of the above is that the current glClear() clears
> don't get a chance to be deferred.  This was observed in Chrome which
> clears an attachment with an emulated format, then switches
> framebuffers.
>
> Additionally, if the render pass had already been started, the deferred
> clears could have become inlined instead of breaking the render pass.
> Although, it's unlikely for there to be deferred clears when the render
> pass is already open.
>
> This change first identifies which clears need to go through the draw
> path (scissored, masked or as workaround for driver bug).  It merges the
> rest of the clears (that don't need the draw path) with the deferred
> clears.  It then checks deferred clears and applies them by either:
>
> - vkCmdClearAttachments if mid RP
> - Start a new render pass and use loadOps, if any draw-based clear needs
>   to follow.
> - Modify current RP loadOps / defer the clear
>
> Afterwards, the draw-based clears are applied.
>
> Bug: angleproject:4836
> Change-Id: Id4992c78983b199734508c9d4bb18ed3195c91ec
> Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2455167
> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
> Reviewed-by: Jamie Madill <jmadill@chromium.org>
> Reviewed-by: Charlie Lao <cclao@google.com>

TBR=syoussefi@chromium.org,jmadill@chromium.org,cclao@google.com

Change-Id: I85733b3594409df9b96e3d5b34933522c97c42cf
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: angleproject:4836
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2481613Reviewed-by: Tim Van Patten <timvp@google.com>
Commit-Queue: Tim Van Patten <timvp@google.com>