Add uma histogram tracking for the number of submit render passes.

This uma stat can allow us to look a few different things. First we can
look at the distribution of render passes per submit (including mean,
median, ect.). Additionally we can do things like sum the total number
of renderpasses from all submits and divide by the total number of
frames (Compositing.Display.DrawToSwapUs::TotalCount) to get the
average number of render passes per frame and not just submit.

Technically under the hood the ENUMERATION and LINEAR_EXACT macros will
do the same thing and we could just use ENUMERATION here. However to
match how chrome uses their UMA macros it is more correct to use the
LINEAR_EXACT since we aren't counting enum values. Chromes macros
actually have static asserts the values are or are not enums, but the
skia implementations do not.

Includes some minor updates to names to match chromes UMA macro values.

This still requires the chrome implementation of the new macro.

Bug: skia:10871
Change-Id: Idbc4d2fc649bbdefd0952a002c3327cb700b552b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/329776
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Adlai Holler <adlai@google.com>
16 files changed