Make aapt and aidl paths flexible.

Make aapt and aidl paths flexible.

Android-M sdk moved these build-tools to a different directory
and so we need to be able to set them in GYP_DEFINES for M sdk builds.

BUG=None

Committed: https://crrev.com/2a145dab21f4db16cca74c3f2d89fe911cc582b1
Cr-Commit-Position: refs/heads/master@{#332959}

[aurimas (slooooooooow), 2015-06-04 19:12:36]

aurimas@chromium.org changed reviewers:
+ cjhopman@chromium.org, yfriedman@chromium.org

[aurimas (slooooooooow), 2015-06-04 19:12:36]

PTAL

[cjhopman, 2015-06-04 21:13:10]

lgtm

[aurimas (slooooooooow), 2015-06-04 21:22:03]

The CQ bit was checked by aurimas@chromium.org

[commit-bot: I haz the power, 2015-06-04 21:25:01]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1162943008/60001

[commit-bot: I haz the power, 2015-06-04 21:50:26]

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

[commit-bot: I haz the power, 2015-06-04 21:50:26]

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...)

[aurimas (slooooooooow), 2015-06-04 23:04:48]

The CQ bit was checked by aurimas@chromium.org

[commit-bot: I haz the power, 2015-06-04 23:08:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1162943008/60001

[commit-bot: I haz the power, 2015-06-04 23:28:35]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-06-04 23:29:42]

Patchset 4 (id:??) landed as
https://crrev.com/2a145dab21f4db16cca74c3f2d89fe911cc582b1
Cr-Commit-Position: refs/heads/master@{#332959}