android envsetup: Use gyp defines instead of env vars for sdk root and sdk tools.

build/common.gypi

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 1372 matching lines @@
         'variables': {
           'variables': {
              # Unfortuantely we have to use absolute paths to the SDK/NDK beause
              # they're passed to ant which uses a different relative path from
              # gyp.
              'android_ndk_root%': '<!(cd <(DEPTH) && pwd -P)/third_party/android_tools/ndk/',
              'android_sdk_root%': '<!(cd <(DEPTH) && pwd -P)/third_party/android_tools/sdk/',
              'android_host_arch%': '<!(uname -m)',
              # Android API-level of the SDK used for compilation.
              'android_sdk_version%': '19',
-             # Android SDK build tools (e.g. dx, aapt, aidl)
-             'android_sdk_tools%': '<!(/bin/echo -n ${ANDROID_SDK_TOOLS})',
              'host_os%': "<!(uname -s | sed -e 's/Linux/linux/;s/Darwin/mac/')",
           },
           # Copy conditionally-set variables out one scope.
           'android_ndk_root%': '<(android_ndk_root)',
           'android_sdk_root%': '<(android_sdk_root)',
           'android_sdk_version%': '<(android_sdk_version)',
-          'android_sdk_tools%': '<(android_sdk_tools)',
           'android_stlport_root': '<(android_ndk_root)/sources/cxx-stl/stlport',
           'host_os%': '<(host_os)',
 
           'android_sdk%': '<(android_sdk_root)/platforms/android-<(android_sdk_version)',
+          # Android SDK build tools (e.g. dx, aapt, aidl)
+          'android_sdk_tools%': '<(android_sdk_root)/build-tools/<(android_sdk_version).0.0',

[Torne, 2014/02/17 12:14:19]

I don't think this is correct; I think the current sdk tools version being
19.0.0 is only a coincidence and this isn't necessarily the same as
android_sdk_version. The tools are updated independently of the API level.

[Nico, 2014/02/17 16:20:21]

Are you sure? They were updated at the same time the last time:
https://codereview.chromium.org/63153014

frankf thought a similar patch was ok (
https://codereview.chromium.org/download/issue167643002_200001.diff )

(I'm aware that in 18, the sdk tools folder was in 18.0.1 and not 18.0.0 – but
under the assumption that when one upgrades the sdk one wants to upgrade the sdk
tools too, having one reference the other still seems better as this makes it
impossible to forget about one of them. And if ".0.0" is wrong in some version,
one will get a try error when upgrading the version variable but forgetting
about ".0.0".)

[Yaron, 2014/02/18 18:55:51]

Two things come to mind:
1) When we first getting the SDK tools to work, we had to rely on a specific
revision of SDK tools so Torne's point of them being revved independently is
true, however, we did rely more heavily on the SDK-provided tooling at the time.
2) The android build for third party apps are switching from ant to gradle.
However, since we have gyp, we've tried to fit best within that and so we've
minimized usage of android-provided build tools (not the binaries themselves
necessarily, but more how they're used). I could imagine them deprecating
support for old tools and we may want to keep our old ones limping along for a
time since we really don't use much.
 
Anyway, long story short, I agree it's coincidence and can maintain a separate
define in gyp.

 
           # Android API level 14 is ICS (Android 4.0) which is the minimum
           # platform requirement for Chrome on Android, we use it for native
           # code compilation.
           'conditions': [
             ['target_arch == "ia32"', {
               'android_app_abi%': 'x86',
               'android_gdbserver%': '<(android_ndk_root)/prebuilt/android-x86/gdbserver/gdbserver',
               'android_ndk_sysroot%': '<(android_ndk_root)/platforms/android-14/arch-x86',
               'android_toolchain%': '<(android_ndk_root)/toolchains/x86-4.6/prebuilt/<(host_os)-<(android_host_arch)/bin',
@@ skipping 3562 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }