Port r288424 to gn.

Port r288424 to gn.

BUG=none
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=288746

[Nico, 2014-08-10 18:46:41]

Two questions:
1. This seems to work (at least the trybot is green), but having to check
cpu_arch is annoying. Why isn't there just a $android_toolchain_root like in
gyp? Is there a better way of doing this?
2. This too also exists in native_client/build/config/compiler/BUILD.gn . Will
this change get mirrored to there automatically?

[brettw, 2014-08-11 16:34:03]

On 2014/08/10 18:46:41, Nico (very away) wrote:
> Two questions:
> 1. This seems to work (at least the trybot is green), but having to check
> cpu_arch is annoying. Why isn't there just a $android_toolchain_root like in
> gyp? Is there a better way of doing this?

Yes, we should just define the value you want in
build/config/android/config.gni. There's already an if block for the cpu arch at
the bottom of the "Directories and files" section, just define the
"android_toolchain_root" to be the arm_android_toolchain_root or whatever.

We've just never need the current one before (these are only used by the
toolchain setup which runs only in the default toolchain, so it needs all of
them defined).

> 2. This too also exists in native_client/build/config/compiler/BUILD.gn . Will
> this change get mirrored to there automatically?

No, I believe Noel keeps the nacl one in sync manually from time-to-time.

[Nico, 2014-08-11 16:57:46]

Done, please take another look.

The generated ninja file looks good to me. I tried to actually build this to
check which ld ends up being used after this change. I ran:

  gn gen //out_gnand/Release '--args=os="android" cpu_arch="arm" is_clang=true'
  ninja -C out_gnand/Release/ libphonenumber_unittests

and got a bunch of

arm-linux-androideabi-g++: error: find-bad-constructs: No such file or directory
arm-linux-androideabi-g++: error: unrecognized command line option
'-fcolor-diagnostics'
arm-linux-androideabi-g++: error: unrecognized command line option '-target
arm-linux-androideabi'
arm-linux-androideabi-g++: error: unrecognized command line option '-Xclang'
arm-linux-androideabi-g++: error: unrecognized command line option '-Xclang'
arm-linux-androideabi-g++: error: unrecognized command line option '-Xclang'


I guess is_clang=true doesn't work with os="android" in gn?

[brettw, 2014-08-11 17:56:38]

> I guess is_clang=true doesn't work with os="android" in gn?

This is correct to my knowledge.

LGTM

[Nico, 2014-08-11 17:57:31]

(cc'ing noel so he can merge this to nacl)

[Nico, 2014-08-11 17:57:34]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2014-08-11 17:59:26]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/thakis@chromium.org/457193002/40001

[commit-bot: I haz the power, 2014-08-11 18:01:25]

Change committed as 288746