[NaCl SDK] nacl_io: Enable isatty running under sel_ldr.

[NaCl SDK] nacl_io: Enable isatty running under sel_ldr.

This change enabled the sel_ldr's isatty() implementation
to be used, which enables color output for gtest and other
terminal-based applications.

Unfortunately this is newlib only right now.

R=binji@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=259043

[binji, 2014-03-18 19:41:17]

https://codereview.chromium.org/59883020/diff/30001/native_client_sdk/src/lib...
File native_client_sdk/src/libraries/nacl_io/passthroughfs/passthrough_fs.cc
(right):

https://codereview.chromium.org/59883020/diff/30001/native_client_sdk/src/lib...
native_client_sdk/src/libraries/nacl_io/passthroughfs/passthrough_fs.cc:101:
return err;
return type is bool. Do we need to change the signature of this function to
Error IsaTTY(int* out_result)?

Hm, yeah KernelProxy::isatty is wrong too.

[Sam Clegg, 2014-03-18 20:03:55]

On 2014/03/18 19:41:17, binji wrote:
>
https://codereview.chromium.org/59883020/diff/30001/native_client_sdk/src/lib...
> File native_client_sdk/src/libraries/nacl_io/passthroughfs/passthrough_fs.cc
> (right):
> 
>
https://codereview.chromium.org/59883020/diff/30001/native_client_sdk/src/lib...
> native_client_sdk/src/libraries/nacl_io/passthroughfs/passthrough_fs.cc:101:
> return err;
> return type is bool. Do we need to change the signature of this function to
> Error IsaTTY(int* out_result)?

Done.

> 
> Hm, yeah KernelProxy::isatty is wrong too.

I think KernelProxy::isatty ok.  I matches the C API and sets errno, right?

[Sam Clegg, 2014-03-18 20:19:40]

Updated Isatty() tests to use EXPECT_EQ(ENOTTY)

[binji, 2014-03-18 20:23:45]

lgtm

[Sam Clegg, 2014-03-24 22:40:41]

Committed patchset #4 manually as r259043 (presubmit successful).