[Android] Add a configurable environment for devil/.

build/android/test_runner.py

Index: build/android/test_runner.py
diff --git a/build/android/test_runner.py b/build/android/test_runner.py
index 6c384b1c6a0be82ff5deedfd931d17a6df12369c..3eb7e44102cb4ae3542c0fbc4277da700680c9af 100755
--- a/build/android/test_runner.py
+++ b/build/android/test_runner.py
@@ -21,6 +21,7 @@ from devil.android import device_blacklist
 from devil.android import device_errors
 from devil.android import device_utils
 from devil.android import ports
+import devil.env
 from devil.utils import reraiser_thread
 from devil.utils import run_tests_helper
 
@@ -117,6 +118,13 @@ def ProcessCommonOptions(args):
     constants.SetOutputDirectory(args.output_directory)
   if args.adb_path:
     constants.SetAdbPath(args.adb_path)
+
+  devil.env.android_sdk = devil.env.android_sdk_config.AndroidSdkConfig(

[jbudorick, 2015/09/09 23:47:07]

Configuring devil's environment is intentionally ugly because it:
 - shouldn't be done often, and
 - shouldn't be easy to do on accident

[perezju, 2015/09/10 09:45:48]

Throwing some ideas: If the intention is that configs shouldn't easily change
after being set. I think, e.g., AndroidSdkConfig should return a named tuple
with all the config values already set, rather than an object with a hidden dict
and properties whose values might change between calls. With a named tuple
values can't be accidentally changed by clients or the environment. This also
tightens things up as we wouldn't be able to set values for non-existent
properties.

Now trying to _read_ from an unset devil.env.android_sdk should either throw an
exception or try to guess some sensible defaults *and fix them* at that time.

+      root_path=constants.ANDROID_SDK_ROOT,
+      adb_path=args.adb_path)
+  devil.env.binaries = devil.env.binary_config.BinaryConfig(
+      binary_dir=constants.GetOutDirectory())
+
   # Some things such as Forwarder require ADB to be in the environment path.
   adb_dir = os.path.dirname(constants.GetAdbPath())
   if adb_dir and adb_dir not in os.environ['PATH'].split(os.pathsep):