GN: Harmonize ARM compiler settings with GYP

GN: Harmonize ARM compiler settings with GYP

This changes various defaults about the ARM compiler setup so
that GN matches what GYP does today:
* Prefix for cross tools is arm-linux-gnueabihf- not arm-linux-gnueabi-
* arm_float_abi defaults to hard for non-Android ARMv7
* Non-CrOS ARM builds use the ARM sysroot by default
  (the one installed by install-build-deps.sh --arm)
* Define a clang_arm toolchain, pass it the -no-integrated and
  -target arm-linux-gnueabihf and switches as GYP does

R=dpranke@chromium.org, sbc@chromium.org
BUG=

Committed: https://crrev.com/cc3a331e1bc91166a5d51fc1fa44fba49d1fb461
Cr-Commit-Position: refs/heads/master@{#350100}

[Sam Clegg, 2015-09-19 08:40:06]

lgtm

https://codereview.chromium.org/1352313002/diff/1/build/config/sysroot.gni
File build/config/sysroot.gni (right):

https://codereview.chromium.org/1352313002/diff/1/build/config/sysroot.gni#ne...
build/config/sysroot.gni:48: sysroot = rebase_path("//mipsel-sysroot/sysroot")
Looks like the mips path is out-of-date too, but maybe thats a different CL?

[Roland McGrath, 2015-09-19 22:27:42]

On 2015/09/19 08:40:06, Sam Clegg wrote:
> lgtm
> 
> https://codereview.chromium.org/1352313002/diff/1/build/config/sysroot.gni
> File build/config/sysroot.gni (right):
> 
>
https://codereview.chromium.org/1352313002/diff/1/build/config/sysroot.gni#ne...
> build/config/sysroot.gni:48: sysroot = rebase_path("//mipsel-sysroot/sysroot")
> Looks like the mips path is out-of-date too, but maybe thats a different CL?

I don't know what the mips situation is and wasn't planning to look into it.

[Roland McGrath, 2015-09-19 22:27:48]

The CQ bit was checked by mcgrathr@chromium.org

[commit-bot: I haz the power, 2015-09-19 22:27:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1352313002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1352313002/1

[commit-bot: I haz the power, 2015-09-19 22:34:49]

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

[commit-bot: I haz the power, 2015-09-19 22:34:50]

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

[Roland McGrath, 2015-09-21 18:22:59]

dpranke: OWNERS review please

[Dirk Pranke, 2015-09-22 01:16:50]

lgtm

[Roland McGrath, 2015-09-22 02:10:22]

The CQ bit was checked by mcgrathr@chromium.org

[commit-bot: I haz the power, 2015-09-22 02:10:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1352313002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1352313002/1

[commit-bot: I haz the power, 2015-09-22 03:25:49]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-22 03:26:31]

Patchset 1 (id:??) landed as
https://crrev.com/cc3a331e1bc91166a5d51fc1fa44fba49d1fb461
Cr-Commit-Position: refs/heads/master@{#350100}