Add UMA entries for web history UMA histograms.

Add UMA entries for web history UMA histograms.

https://codereview.chromium.org/12381081 added UMA histograms for the web
history but no entries were added to the histograms.xml file.

This CL fixes that.

R=isherman@chromium.org
BUG=177073
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=202455

[Sergiu, 2013-05-24 15:57:11]

Please take a look. Thanks.

[jar (doing other things), 2013-05-24 17:42:54]

Steve/Alexei: Can you comment?

[Alexei Svitkine (slow), 2013-05-24 17:58:02]

https://codereview.chromium.org/15821006/diff/1/tools/metrics/histograms/hist...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/15821006/diff/1/tools/metrics/histograms/hist...
tools/metrics/histograms/histograms.xml:8996: web history.
Please mention how this is sampled. Is it when a page is opened, periodically,
etc?

https://codereview.chromium.org/15821006/diff/1/tools/metrics/histograms/hist...
tools/metrics/histograms/histograms.xml:9001: <summary>Whether the web history
query was successful.</summary>
Please add a little bit more context in the comment - what is the web history
query? Is it something that runs when you go to chrome://history? Or is it
related to the omnibox history provider, or ...?

The expanded comment should also make it clear when this is sampled.

Please do the same for the histogram below.

Thanks!

[Sergiu, 2013-05-27 08:27:43]

https://codereview.chromium.org/15821006/diff/1/tools/metrics/histograms/hist...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/15821006/diff/1/tools/metrics/histograms/hist...
tools/metrics/histograms/histograms.xml:8996: web history.
On 2013/05/24 17:58:02, Alexei Svitkine wrote:
> Please mention how this is sampled. Is it when a page is opened, periodically,
> etc?

Done.

https://codereview.chromium.org/15821006/diff/1/tools/metrics/histograms/hist...
tools/metrics/histograms/histograms.xml:9001: <summary>Whether the web history
query was successful.</summary>
On 2013/05/24 17:58:02, Alexei Svitkine wrote:
> Please add a little bit more context in the comment - what is the web history
> query? Is it something that runs when you go to chrome://history? Or is it
> related to the omnibox history provider, or ...?
> 
> The expanded comment should also make it clear when this is sampled.
> 
> Please do the same for the histogram below.
> 
> Thanks!

Done, tell me what you think now.

[Alexei Svitkine (slow), 2013-05-27 15:14:12]

lgtm

[commit-bot: I haz the power, 2013-05-27 16:45:55]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/sergiu@chromium.org/15821006/6001

[jar (doing other things), 2013-05-27 16:49:53]

lgtm

[commit-bot: I haz the power, 2013-05-27 18:51:03]

Change committed as 202455