Use precisely sized integer types in histograms code.

Use precisely sized integer types in histograms code.

BUG=none
TEST=none
R=asvitkine@chromium.org

Committed: https://crrev.com/bed49a668bf2d496416ae7346d7d3a1f42e44260
Cr-Commit-Position: refs/heads/master@{#292340}

[Ilya Sherman, 2014-08-27 22:45:12]

I'm pretty sure that this is equivalent to the existing code, but more explicit.
 WDYT?

[Alexei Svitkine (slow), 2014-08-28 04:38:21]

lgtm

[Ilya Sherman, 2014-08-28 05:15:33]

The CQ bit was checked by isherman@chromium.org

[commit-bot: I haz the power, 2014-08-28 05:16:24]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/isherman@chromium.org/511903003/1

[commit-bot: I haz the power, 2014-08-28 06:29:51]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/linux_gpu/builds/...)
  android_aosp on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_aosp/bu...)
  android_chromium_gn_compile_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_chromiu...)
  android_clang_dbg_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_clang_d...)
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)
  linux_chromium_gn_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_rel_swarming on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  mac_chromium_rel_swarming on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[commit-bot: I haz the power, 2014-08-28 07:22:22]

Committed patchset #1 (id:1) as 31bd6e7ec6e380a5a1b3abcbb063e6768496416d

[commit-bot: I haz the power, 2014-09-10 02:58:12]

Patchset 1 (id:??) landed as
https://crrev.com/bed49a668bf2d496416ae7346d7d3a1f42e44260
Cr-Commit-Position: refs/heads/master@{#292340}