Cleanup histogram classes mixing SetFlags into FactoryGet arguments...

Cleanup histogram classes mixing SetFlags into FactoryGet arguments

Generic cleanup of histogram class, renaming *FactoryGet to FactoryGet,
along with reformatting.

The macros were cleaned up to use common sub-macros rather than
repeating code as much.

Removed ThreadSafeHistogram (and associated ASSET_HISTOGRAM macros)
since this class was not getting used.

I introduced UMA_HISTOGRAM_ENUMERATION to support the common use
of LinearHistograms to count various enumerated values.

I added a Flags argument to all the FactoryGet routines to help avoid 
needing to call SetFlags each time a new sample is Add()ed.  This also
simplifies the code.

This will all help prepare for a "don't histogram at all" macro setting
so that I can test the impact of the histogram macro calls on
performance (since there are now so many active histograms).

BUG=31206
r=raman.tenneti

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=35295

[Paweł Hajdan Jr., 2009-12-27 20:54:54]

Jim, thanks for the change. It makes the FTP histogram code a lot simpler.

Could you update the comments near the changed code? I marked the two places
that would need an update.

http://codereview.chromium.org/515033/diff/2091/2093
File net/ftp/ftp_network_transaction.cc (right):

http://codereview.chromium.org/515033/diff/2091/2093#newcode1153
net/ftp/ftp_network_transaction.cc:1153: // We use two groups of counters.  In
the first group (counter1), each counter
Please update the no longer relevant parts of the comment (possibly also the
above one).

http://codereview.chromium.org/515033/diff/2091/2094
File net/ftp/ftp_server_type_histograms.cc (right):

http://codereview.chromium.org/515033/diff/2091/2094#newcode15
net/ftp/ftp_server_type_histograms.cc:15: // We use two groups of counters.  In
the first group (counter1), each counter
Please update the no longer relevant parts of the comment (possibly also the
above one).

[jar (doing other things), 2009-12-28 01:08:30]

Made changes in comments per Pawel's request.

Removed ThreadSafeHistogram (which was not being used) along with
ASSET_HISTOGRAM macros.

http://codereview.chromium.org/515033/diff/2091/2093
File net/ftp/ftp_network_transaction.cc (right):

http://codereview.chromium.org/515033/diff/2091/2093#newcode1153
net/ftp/ftp_network_transaction.cc:1153: // We use two groups of counters.  In
the first group (counter1), each counter
On 2009/12/27 20:54:54, Paweł Hajdan Jr. wrote:
> Please update the no longer relevant parts of the comment (possibly also the
> above one).

Done.

http://codereview.chromium.org/515033/diff/2091/2094
File net/ftp/ftp_server_type_histograms.cc (right):

http://codereview.chromium.org/515033/diff/2091/2094#newcode15
net/ftp/ftp_server_type_histograms.cc:15: // We use two groups of counters.  In
the first group (counter1), each counter
On 2009/12/27 20:54:54, Paweł Hajdan Jr. wrote:
> Please update the no longer relevant parts of the comment (possibly also the
> above one).

Done.

[raman, 2009-12-28 06:50:21]

LGTM to jim.

thanks,
raman