AlternativeServiceServers - Added couple of histograms to measure if

AlternativeServiceServers - Added couple of histograms to measure if
memory cache has more entries or preferences file has more entries for
AlternativeServiceServers.

BUG=568386
R=asvitkine@chromium.org, rch@chromium.org, bnc@chromium.org

Committed: https://crrev.com/0bd49c41cc6789934a8c93345f19d8f56e3eafc0
Cr-Commit-Position: refs/heads/master@{#366196}

[ramant (doing other things), 2015-12-18 00:24:06]

Hi Alexei, Bence and Ryan,
  Bence asked a question if PutBack is better than Swap in 
  https://codereview.chromium.org/1515243003/

  For loading of server data from Preferences, for most of the users
  we load the data once during startup (at that time there is a possibility
  some preconnects have happened and there is data in the memory. On my
  machine, my memory cache's size is 0, but in theory it is possible).

  Wanted to see if memory will have more entries than disk, thus added
  these histograms. 

  Will delete these histograms as soon as we get some data after QUIC is
enabled.

thanks
raman

[Ryan Hamilton, 2015-12-18 19:45:11]

lgtm

[Alexei Svitkine (slow), 2015-12-18 19:58:48]

lgtm % comments

https://codereview.chromium.org/1537463004/diff/1/net/http/http_server_proper...
File net/http/http_server_properties_impl.cc (right):

https://codereview.chromium.org/1537463004/diff/1/net/http/http_server_proper...
net/http/http_server_properties_impl.cc:65: } else {
Should you check that size_diff isn't 0? It's fine to log it for 0 too, but in
that case you should expand the histogram description to mention that case.

https://codereview.chromium.org/1537463004/diff/1/tools/metrics/histograms/hi...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1537463004/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:22182: +    preferences.
Mention that it's only logged when positive and point to the other histogram.
Same for the other one.

[ramant (doing other things), 2015-12-18 21:34:55]

Thanks Alexei. PTAL (would appreciate better description for histograms).

https://codereview.chromium.org/1537463004/diff/1/net/http/http_server_proper...
File net/http/http_server_properties_impl.cc (right):

https://codereview.chromium.org/1537463004/diff/1/net/http/http_server_proper...
net/http/http_server_properties_impl.cc:65: } else {
On 2015/12/18 19:58:48, Alexei Svitkine (slow) wrote:
> Should you check that size_diff isn't 0? It's fine to log it for 0 too, but in
> that case you should expand the histogram description to mention that case.

Good point. Changed the histogram name and description.

Done.

https://codereview.chromium.org/1537463004/diff/1/tools/metrics/histograms/hi...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1537463004/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:22182: +    preferences.
On 2015/12/18 19:58:48, Alexei Svitkine (slow) wrote:
> Mention that it's only logged when positive and point to the other histogram.
> Same for the other one.

Added comments. PTAL.

Done.

[Alexei Svitkine (slow), 2015-12-18 21:37:16]

lgtm

[ramant (doing other things), 2015-12-18 21:45:47]

The CQ bit was checked by rtenneti@chromium.org

[ramant (doing other things), 2015-12-18 21:45:47]

The patchset sent to the CQ was uploaded after l-g-t-m from rch@chromium.org
Link to the patchset: https://codereview.chromium.org/1537463004/#ps20001
(title: "fix comments to Patch Set 1")

[commit-bot: I haz the power, 2015-12-18 21:46:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1537463004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1537463004/20001

[commit-bot: I haz the power, 2015-12-18 23:13:19]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-12-18 23:14:01]

Description was changed from

==========
AlternativeServiceServers - Added couple of histograms to measure if
memory cache has more entries or preferences file has more entries for
AlternativeServiceServers.

BUG=568386
R=asvitkine@chromium.org, rch@chromium.org, bnc@chromium.org
==========

to

==========
AlternativeServiceServers - Added couple of histograms to measure if
memory cache has more entries or preferences file has more entries for
AlternativeServiceServers.

BUG=568386
R=asvitkine@chromium.org, rch@chromium.org, bnc@chromium.org

Committed: https://crrev.com/0bd49c41cc6789934a8c93345f19d8f56e3eafc0
Cr-Commit-Position: refs/heads/master@{#366196}
==========

[commit-bot: I haz the power, 2015-12-18 23:14:03]

Patchset 2 (id:??) landed as
https://crrev.com/0bd49c41cc6789934a8c93345f19d8f56e3eafc0
Cr-Commit-Position: refs/heads/master@{#366196}