cc: Handle overflow/underflow in MathUtil::RoundUp/RoundDown functions.

cc: Handle overflow/underflow in MathUtil::RoundUp/RoundDown functions.

The existing functions are renamed as given below.
RoundUp -> UncheckedRoundUp
RoundDown -> UncheckedRoundDown

These functions add the DCHECKs for verifying overflow/underflow by
using VerifyOverflow and VerifyUnderflow functions. The checked
versions CheckedRoundUp and CheckedRoundDown are added to implicitly
check the overflow and underflow conditions. These versions CRASH if
rounded up/down values overflow/underflow.

P.N. All the rounding functions in current codebase have been replaced
by unchecked versions.

Following new unittests are added.
MathUtilTest.RoundUpOverFlow
MathUtilTest.RoundDownUnderFlow

BUG=515566
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Committed: https://crrev.com/239014d69890b6441de528a08340eda25747ecf2
Cr-Commit-Position: refs/heads/master@{#342049}

[prashant.n, 2015-08-03 13:29:00]

The CQ bit was checked by prashant.n@samsung.com to run a CQ dry run

[commit-bot: I haz the power, 2015-08-03 13:29:31]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1266103005/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1266103005/1

[commit-bot: I haz the power, 2015-08-03 13:29:33]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-03 13:29:33]

Dry run: No L-G-T-M from a valid reviewer yet. Only full committers are
accepted.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[a.suchit2, 2015-08-03 13:31:36]

The CQ bit was checked by a.suchit@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-03 13:32:11]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1266103005/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1266103005/1

[prashant.n, 2015-08-03 13:47:05]

prashant.n@samsung.com changed reviewers:
+ ajuma@chromium.org, danakj@chromium.org, enne@chromium.org,
ericrk@chromium.org

[prashant.n, 2015-08-03 13:47:05]

PTAL

[commit-bot: I haz the power, 2015-08-03 14:35:43]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-03 14:35:44]

Dry run: Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[prashant.n, 2015-08-04 18:11:12]

Please review this.

[vmpstr, 2015-08-04 18:17:23]

vmpstr@chromium.org changed reviewers:
+ vmpstr@chromium.org

[vmpstr, 2015-08-04 18:17:23]

https://codereview.chromium.org/1266103005/diff/20001/cc/base/math_util.h
File cc/base/math_util.h (right):

https://codereview.chromium.org/1266103005/diff/20001/cc/base/math_util.h#new...
cc/base/math_util.h:102: return mul
"a ? b : false" is better written as "a && b"

https://codereview.chromium.org/1266103005/diff/20001/cc/base/math_util.h#new...
cc/base/math_util.h:120: // Dies with a CRASH(), if rounding up a given |n|
overflows T.
nit: You should say something like "Similar to UncheckedRoundUp, but dies with a
CRASH(), ..."

just so you document what the function does as well as the difference from the
unchecked version.

https://codereview.chromium.org/1266103005/diff/20001/cc/base/math_util.h#new...
cc/base/math_util.h:132: return mul
Same here

[prashant.n, 2015-08-05 13:57:16]

PTAL

[vmpstr, 2015-08-05 17:50:35]

lgtm

[prashant.n, 2015-08-05 18:03:37]

The CQ bit was checked by prashant.n@samsung.com

[commit-bot: I haz the power, 2015-08-05 18:04:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1266103005/80001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1266103005/80001

[commit-bot: I haz the power, 2015-08-05 19:03:13]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-05 19:03:14]

Try jobs failed on following builders:
  win_chromium_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[prashant.n, 2015-08-06 01:26:03]

The CQ bit was checked by prashant.n@samsung.com

[commit-bot: I haz the power, 2015-08-06 01:27:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1266103005/80001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1266103005/80001

[commit-bot: I haz the power, 2015-08-06 02:23:07]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2015-08-06 02:23:50]

Patchset 5 (id:??) landed as
https://crrev.com/239014d69890b6441de528a08340eda25747ecf2
Cr-Commit-Position: refs/heads/master@{#342049}