Add Drive.MetadataDBValidityCheckFailureReason UMA histogram

Add Drive.MetadataDBValidityCheckFailureReason UMA histogram

According to the latest data, about 0.02% of DB initialization results in discarding old DB which may contain users' unsynced data.
About 2/3 of these failures are due to errors detected by CheckValidity().

Add UMA histogram to help future developers improve this.

BUG=None

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=288010

[kinaba, 2014-08-05 06:00:15]

https://codereview.chromium.org/445513002/diff/1/chrome/browser/chromeos/driv...
File chrome/browser/chromeos/drive/resource_metadata_storage.cc (right):

https://codereview.chromium.org/445513002/diff/1/chrome/browser/chromeos/driv...
chrome/browser/chromeos/drive/resource_metadata_storage.cc:950:
DB_INIT_MAX_VALUE);
CHECK_VALIDITY_FAILURE_MAX_VALUE? (ditto for everywhere)

https://codereview.chromium.org/445513002/diff/1/tools/metrics/histograms/his...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/445513002/diff/1/tools/metrics/histograms/his...
tools/metrics/histograms/histograms.xml:5293: +   
enum="DriveMetadataDBVlidityCheckFailureReason">
CHECK_VALIDITY_FAILURE_MAX_VALUE

https://codereview.chromium.org/445513002/diff/1/tools/metrics/histograms/his...
tools/metrics/histograms/histograms.xml:37763: +<enum
name="DriveMetadataDBVlidityCheckFailureReason" type="int">
ditto

[hashimoto, 2014-08-05 06:08:09]

https://codereview.chromium.org/445513002/diff/1/chrome/browser/chromeos/driv...
File chrome/browser/chromeos/drive/resource_metadata_storage.cc (right):

https://codereview.chromium.org/445513002/diff/1/chrome/browser/chromeos/driv...
chrome/browser/chromeos/drive/resource_metadata_storage.cc:950:
DB_INIT_MAX_VALUE);
On 2014/08/05 06:00:14, kinaba wrote:
> CHECK_VALIDITY_FAILURE_MAX_VALUE? (ditto for everywhere)

Ugh, done.

https://codereview.chromium.org/445513002/diff/1/tools/metrics/histograms/his...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/445513002/diff/1/tools/metrics/histograms/his...
tools/metrics/histograms/histograms.xml:5293: +   
enum="DriveMetadataDBVlidityCheckFailureReason">
On 2014/08/05 06:00:14, kinaba wrote:
> CHECK_VALIDITY_FAILURE_MAX_VALUE

Fixed typo.

https://codereview.chromium.org/445513002/diff/1/tools/metrics/histograms/his...
tools/metrics/histograms/histograms.xml:37763: +<enum
name="DriveMetadataDBVlidityCheckFailureReason" type="int">
On 2014/08/05 06:00:14, kinaba wrote:
> ditto

Fixed typo.

[kinaba, 2014-08-05 06:11:57]

lgtm

https://codereview.chromium.org/445513002/diff/1/tools/metrics/histograms/his...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/445513002/diff/1/tools/metrics/histograms/his...
tools/metrics/histograms/histograms.xml:5293: +   
enum="DriveMetadataDBVlidityCheckFailureReason">
On 2014/08/05 06:08:09, hashimoto wrote:
> On 2014/08/05 06:00:14, kinaba wrote:
> > CHECK_VALIDITY_FAILURE_MAX_VALUE
> 
> Fixed typo.

Eh, sorry for my garbage review comment (caused by copy-and-paste failure).
Yes, what I meant is the typo "Vlidity", thanks :))

[hashimoto, 2014-08-05 06:21:48]

Alexei, could you take a look at this change as an owner of histograms.xml?

[Alexei Svitkine (slow), 2014-08-05 13:18:16]

https://codereview.chromium.org/445513002/diff/40001/chrome/browser/chromeos/...
File chrome/browser/chromeos/drive/resource_metadata_storage.cc (right):

https://codereview.chromium.org/445513002/diff/40001/chrome/browser/chromeos/...
chrome/browser/chromeos/drive/resource_metadata_storage.cc:948:
UMA_HISTOGRAM_ENUMERATION("Drive.MetadataDBValidityCheckFailureReason",
Nit: Each histogram macro adds a lot of machine code at the callsite. Can you
instead add a helper function that records the macro and takes the enum value to
record and then call it from every place you record this histogram? This will
avoid bloating the binary.

[hashimoto, 2014-08-06 03:52:20]

https://codereview.chromium.org/445513002/diff/40001/chrome/browser/chromeos/...
File chrome/browser/chromeos/drive/resource_metadata_storage.cc (right):

https://codereview.chromium.org/445513002/diff/40001/chrome/browser/chromeos/...
chrome/browser/chromeos/drive/resource_metadata_storage.cc:948:
UMA_HISTOGRAM_ENUMERATION("Drive.MetadataDBValidityCheckFailureReason",
On 2014/08/05 13:18:16, Alexei Svitkine wrote:
> Nit: Each histogram macro adds a lot of machine code at the callsite. Can you
> instead add a helper function that records the macro and takes the enum value
to
> record and then call it from every place you record this histogram? This will
> avoid bloating the binary.

Done.

[Alexei Svitkine (slow), 2014-08-06 15:55:48]

LGTM % comment

https://codereview.chromium.org/445513002/diff/80001/tools/metrics/histograms...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/445513002/diff/80001/tools/metrics/histograms...
tools/metrics/histograms/histograms.xml:5294: + 
<owner>joshwoodward@google.com</owner>
Nit: @chromium.org accounts are generally preferred. Also, shouldn't you be the
owner of this metric? We do support multiple owner tags if there's more than one
person who should be listed.

[hashimoto, 2014-08-07 04:32:01]

https://codereview.chromium.org/445513002/diff/80001/tools/metrics/histograms...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/445513002/diff/80001/tools/metrics/histograms...
tools/metrics/histograms/histograms.xml:5294: + 
<owner>joshwoodward@google.com</owner>
On 2014/08/06 15:55:48, Alexei Svitkine wrote:
> Nit: @chromium.org accounts are generally preferred. Also, shouldn't you be
the
> owner of this metric? We do support multiple owner tags if there's more than
one
> person who should be listed.

Replaced with chromium.org accounts of appropriate owners.

[hashimoto, 2014-08-07 04:32:05]

The CQ bit was checked by hashimoto@chromium.org

[commit-bot: I haz the power, 2014-08-07 04:33:57]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/hashimoto@chromium.org/445513002/100001

[commit-bot: I haz the power, 2014-08-07 08:19:05]

Change committed as 288010