The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/adhd/+/f53d9eb4eebc4300610682f8f5728593ab103e2a

commit f53d9eb4eebc4300610682f8f5728593ab103e2a
Author: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Date: Sun Sep 16 15:16:33 2018

CRAS: server_metrics - Log stream configurations

When adding new stream, metrics will log stream configurations to UMA. It
can help us do some analysis.

In this change, we record stream flag, block size, sampling rate and sample
format of one stream.

BUG= chromium:880163 
TEST=Configure of stream can be recorded well on peppy.

Change-Id: I24e68d591eb9cceef304c1efbf2b99ad31c7cab9
Reviewed-on: https://chromium-review.googlesource.com/1220929
Commit-Ready: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Tested-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Reviewed-by: Cheng-Yi Chiang <cychiang@chromium.org>

[modify] https://crrev.com/f53d9eb4eebc4300610682f8f5728593ab103e2a/cras/src/server/cras_server_metrics.c
[modify] https://crrev.com/f53d9eb4eebc4300610682f8f5728593ab103e2a/cras/src/tests/server_metrics_unittest.cc
[modify] https://crrev.com/f53d9eb4eebc4300610682f8f5728593ab103e2a/cras/src/server/cras_server_metrics.h
[modify] https://crrev.com/f53d9eb4eebc4300610682f8f5728593ab103e2a/cras/src/common/cras_metrics.h
[modify] https://crrev.com/f53d9eb4eebc4300610682f8f5728593ab103e2a/cras/src/server/cras_rclient.c
[modify] https://crrev.com/f53d9eb4eebc4300610682f8f5728593ab103e2a/cras/src/common/cras_metrics.c
[modify] https://crrev.com/f53d9eb4eebc4300610682f8f5728593ab103e2a/cras/src/tests/rclient_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4d26279bbdbc0cb7bec1f8ee4f499f879f2006e6

commit 4d26279bbdbc0cb7bec1f8ee4f499f879f2006e6
Author: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Date: Mon Sep 17 04:05:55 2018

CRAS: add histograms for stream configurations

The change is related to CL:1220929. Add histogram infomation in
histograms.xml to make the histogram visible on chromedashboard.

BUG= chromium:880163 

Change-Id: I01f2805d85cadf2e7c4793eb37909800a5ba9dc2
Reviewed-on: https://chromium-review.googlesource.com/1223954
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591611}
[modify] https://crrev.com/4d26279bbdbc0cb7bec1f8ee4f499f879f2006e6/tools/metrics/histograms/enums.xml
[modify] https://crrev.com/4d26279bbdbc0cb7bec1f8ee4f499f879f2006e6/tools/metrics/histograms/histograms.xml