Histogram - Checks to cacth corruption in bucket ranges

Histogram - Checks to cacth corruption in bucket ranges
when histogram is created. 

We will back out this change. This is temporary to catch
corruptions as early as possible.

TBR=jar,kaiwang
TEST=base unittests
BUG=140688
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=151415

[kaiwang, 2012-08-14 01:23:35]

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc
File base/metrics/histogram.cc (right):

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc#n...
base/metrics/histogram.cc:145: for (size_t index = 0; index <
histogram.bucket_count(); ++index) {
index < histogram.bucket_count() + 1;

num of ranges is num of bucket plus 1

[ramant (doing other things), 2012-08-14 01:28:47]

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc
File base/metrics/histogram.cc (right):

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc#n...
base/metrics/histogram.cc:145: for (size_t index = 0; index <
histogram.bucket_count(); ++index) {
On 2012/08/14 01:23:35, kaiwang wrote:
> index < histogram.bucket_count() + 1;
> 
> num of ranges is num of bucket plus 1

kaewang and I have talked. We will leave this as is (similar to the code in
FindCorruption) to reduce the number of variables and to duplicate the exact
crashes as we were seeing.

[kaiwang, 2012-08-14 01:37:40]

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc
File base/metrics/histogram.cc (right):

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc#n...
base/metrics/histogram.cc:145: for (size_t index = 0; index <
histogram.bucket_count(); ++index) {
This is temporary code, so I think it's not necessary to match the original
wrong behavior?

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc#n...
base/metrics/histogram.cc:870: 
also add validation here?

[kaiwang, 2012-08-14 01:40:13]

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc
File base/metrics/histogram.cc (right):

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc#n...
base/metrics/histogram.cc:145: for (size_t index = 0; index <
histogram.bucket_count(); ++index) {
thinking it again, fix the behavior may lead to more CHECK failure. Just leave
it like this :)

[ramant (doing other things), 2012-08-14 01:49:45]

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc
File base/metrics/histogram.cc (right):

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc#n...
base/metrics/histogram.cc:145: for (size_t index = 0; index <
histogram.bucket_count(); ++index) {
On 2012/08/14 01:40:13, kaiwang wrote:
> thinking it again, fix the behavior may lead to more CHECK failure. Just leave
> it like this :)

+1. I agree.

http://codereview.chromium.org/10826293/diff/9001/base/metrics/histogram.cc#n...
base/metrics/histogram.cc:870: 
On 2012/08/14 01:37:40, kaiwang wrote:
> also add validation here?

Done.

[kaiwang, 2012-08-14 01:58:47]

lgtm