Fix and enable MSVC warning C4018 for base/.

Fix and enable MSVC warning C4018 for base/.

BUG=398202
TEST=none

Committed: https://crrev.com/189c4d96ad21ba65a063200cf3179aef1e6e1d46
Cr-Commit-Position: refs/heads/master@{#339589}

[Peter Kasting, 2015-07-20 23:14:19]

pkasting@chromium.org changed reviewers:
+ thakis@chromium.org

[Nico, 2015-07-20 23:39:27]

https://codereview.chromium.org/1246833003/diff/1/base/files/file_enumerator_...
File base/files/file_enumerator_win.cc (right):

https://codereview.chromium.org/1246833003/diff/1/base/files/file_enumerator_...
base/files/file_enumerator_win.cc:34:
static_cast<ULONGLONG>(std::numeric_limits<int64>::max()));
Does std::numeric_limits<ULONGLONG>::max() not work?

[Peter Kasting, 2015-07-20 23:45:50]

https://codereview.chromium.org/1246833003/diff/1/base/files/file_enumerator_...
File base/files/file_enumerator_win.cc (right):

https://codereview.chromium.org/1246833003/diff/1/base/files/file_enumerator_...
base/files/file_enumerator_win.cc:34:
static_cast<ULONGLONG>(std::numeric_limits<int64>::max()));
On 2015/07/20 at 23:39:27, Nico wrote:
> Does std::numeric_limits<ULONGLONG>::max() not work?

That's not correct.  We're going to cast a ULONGLONG to an int64, so we want to
check that it's not over the int64 max.  Checking against ULONGLONG max would
tautologically be true.

[Nico, 2015-07-20 23:48:10]

lgtm

https://codereview.chromium.org/1246833003/diff/1/base/files/file_enumerator_...
File base/files/file_enumerator_win.cc (right):

https://codereview.chromium.org/1246833003/diff/1/base/files/file_enumerator_...
base/files/file_enumerator_win.cc:34:
static_cast<ULONGLONG>(std::numeric_limits<int64>::max()));
On 2015/07/20 23:45:50, Peter Kasting wrote:
> On 2015/07/20 at 23:39:27, Nico wrote:
> > Does std::numeric_limits<ULONGLONG>::max() not work?
> 
> That's not correct.  We're going to cast a ULONGLONG to an int64, so we want
to
> check that it's not over the int64 max.  Checking against ULONGLONG max would
> tautologically be true.

Ah, I see.

[Peter Kasting, 2015-07-21 00:36:44]

The CQ bit was checked by pkasting@chromium.org

[commit-bot: I haz the power, 2015-07-21 00:37:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1246833003/1

[commit-bot: I haz the power, 2015-07-21 01:34:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-21 01:35:43]

Patchset 1 (id:??) landed as
https://crrev.com/189c4d96ad21ba65a063200cf3179aef1e6e1d46
Cr-Commit-Position: refs/heads/master@{#339589}