Reland of place system IO calls in chromecast/crash with Chrome utilities.

Reland of place system IO calls in chromecast/crash with Chrome utilities. (patchset #1 id:1 of https://codereview.chromium.org/1239083005/)

Reason for revert:
The offending test case shall be guarded with ENABLE_THREAD_RESTRICTIONS.

Original issue's description:
> Revert of Replace system IO calls in chromecast/crash with Chrome utilities. (patchset #9 id:160001 of https://codereview.chromium.org/1227963002/)
>
> Reason for revert:
> Breaks CastCrashReporterClientTest.EndToEndTestOnIORestrictedThread:
>
> https://build.chromium.org/p/chromium.linux/builders/Cast%20Linux/builds/2709
>
> Original issue's description:
> > Replace system IO calls in chromecast/crash with Chrome utilities.
> >
> > System IO calls had been used to avoid thread IO restrictions in the
> > crash handler. This change replaces each of these calls with the more
> > platform-independent, stable Chrome IO utilities from ::base. Thread
> > restrictions are disabled in crash_util.cc.
> >
> > BUG= b/22329428
> >
> > Committed: https://crrev.com/4927df40d0342522fc268f884835b43f9004549e
> > Cr-Commit-Position: refs/heads/master@{#339161}
>
> TBR=wzhong@chromium.org,bcf@google.com,gunsch@chromium.org,gfhuang@chromium.org,slan@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG= b/22329428
>
> Committed: https://crrev.com/4306386450441c312f0e94af12074ae1534b4117
> Cr-Commit-Position: refs/heads/master@{#339183}

BUG= b/22329428

Committed: https://crrev.com/5ad01a654b3aef2391dfe3b387af11a88e0d34b1
Cr-Commit-Position: refs/heads/master@{#339280}

[slan, 2015-07-17 16:37:37]

Created Reland of place system IO calls in chromecast/crash with Chrome
utilities.

[slan, 2015-07-17 17:15:45]

This patch is verified locally and ready for review.

The IO-restricted thread test is only run when ENABLE_THREAD_RESTRICTIONS is set
for the build. This means that it will currently not be run for public builds,
but will run on internal builds.

[slan, 2015-07-17 17:20:22]

On 2015/07/17 17:15:45, slan wrote:
> This patch is verified locally and ready for review.
> 
> The IO-restricted thread test is only run when ENABLE_THREAD_RESTRICTIONS is
set
> for the build. This means that it will currently not be run for public builds,
> but will run on internal builds.

Clarification: 

It will not run on public *Release* builds. It should still run on public Debug
builds (because NDEBUG should not be set).

[gunsch, 2015-07-17 17:24:57]

lgtm

[slan, 2015-07-17 17:25:12]

The CQ bit was checked by slan@chromium.org

[commit-bot: I haz the power, 2015-07-17 17:26:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1240843003/170001

[commit-bot: I haz the power, 2015-07-17 17:51:53]

Committed patchset #2 (id:170001)

[commit-bot: I haz the power, 2015-07-17 17:52:52]

Patchset 2 (id:??) landed as
https://crrev.com/5ad01a654b3aef2391dfe3b387af11a88e0d34b1
Cr-Commit-Position: refs/heads/master@{#339280}