Reland "[Paint Preview] Split PaintPreviewCompositor memory metrics from the...

Reland "[Paint Preview] Split PaintPreviewCompositor memory metrics from the general Utility process metrics"

This is a reland of 8711fb9a

//components/services/paint_preview_compositor/public/mojom:mojom
is now added to process_memory_metrics_emitter.cc dependencies in
chrome/browser/BUILD.gn to fix the dependency error.

Original change's description:
> [Paint Preview] Split PaintPreviewCompositor memory metrics from the general Utility process metrics
>
> Change-Id: I6067aad3959c054181389c1e1b82e464eacd9a4b
> Bug: 1135217
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2441263


> Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
> Reviewed-by: François Doray <fdoray@chromium.org>
> Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
> Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
> Commit-Queue: Yashar Dabiran <yashard@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#815285}

Bug: 1135217
Change-Id: I7c72463b23060b5e352c4421be5b14d1fee4c574
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2462640


Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Reviewed-by: François Doray <fdoray@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Yashar Dabiran <yashard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816662}