Use the exact-width integer types defined in <stdint.h> rather than

Use the exact-width integer types defined in <stdint.h> rather than
"base/basictypes.h" in net/base/mime_sniffer*.

R=asanka@chromium.org
BUG=488550
TEST=none

Committed: https://crrev.com/e2a366743c9b1b511cbcc9e30cd5ab3b8860f070
Cr-Commit-Position: refs/heads/master@{#333098}

[asanka, 2015-06-04 20:06:54]

lgtm

[wtc, 2015-06-04 20:28:42]

The CQ bit was checked by wtc@chromium.org

[commit-bot: I haz the power, 2015-06-04 20:29:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1151353005/1

[commit-bot: I haz the power, 2015-06-04 21:45:41]

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

[commit-bot: I haz the power, 2015-06-04 21:45:42]

Try jobs failed on following builders:
  android_chromium_gn_compile_rel on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/android_chromiu...)

[wtc, 2015-06-05 17:42:38]

The CQ bit was checked by wtc@chromium.org

[commit-bot: I haz the power, 2015-06-05 17:43:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1151353005/1

[commit-bot: I haz the power, 2015-06-05 18:33:37]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-05 18:35:29]

Patchset 1 (id:??) landed as
https://crrev.com/e2a366743c9b1b511cbcc9e30cd5ab3b8860f070
Cr-Commit-Position: refs/heads/master@{#333098}