[Android] Add a configurable environment for devil/. (RELAND)

build/android/devil/devil_env.py

Index: build/android/devil/devil_env.py
diff --git a/build/android/devil/devil_env.py b/build/android/devil/devil_env.py
new file mode 100644
index 0000000000000000000000000000000000000000..5669fd2e0a128d63123036ae7e6e0f726c418833
--- /dev/null
+++ b/build/android/devil/devil_env.py
@@ -0,0 +1,94 @@
+# Copyright 2015 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.
+
+import json
+import os
+import sys
+import tempfile
+import threading
+
+# TODO(jbudorick): Update this once dependency_manager moves to catapult.
+_TELEMETRY_PATH = os.path.abspath(os.path.join(
+    os.path.dirname(__file__), os.pardir, os.pardir, os.pardir,
+    'tools', 'telemetry'))
+sys.path.append(_TELEMETRY_PATH)
+from catapult_base import dependency_manager # pylint: disable=import-error
+
+_ANDROID_BUILD_TOOLS = {'aapt', 'dexdump', 'split-select'}
+
+_DEVIL_DEFAULT_CONFIG = os.path.abspath(os.path.join(
+    os.path.dirname(__file__), 'devil_dependencies.json'))
+
+
+class _Environment(object):
+
+  def __init__(self):
+    self._config = None
+    self._config_init_lock = threading.Lock()
+    self._dm = None
+
+  def Initialize(self, configs=None, config_files=None):
+    """Initialize devil's environment from configuration files.
+
+    This uses all configurations provided via |configs| and |config_files|
+    to determine the locations of devil's dependencies. Configurations should
+    all take the form described by catapult_base.dependency_manager.BaseConfig.
+    If no configurations are provided, a default one will be used if available.
+
+    Args:
+      configs: An optional list of dict configurations.
+      config_files: An optional list of files to load
+    """
+
+    # Make sure we only initialize self._config once.
+    with self._config_init_lock:
+      if self._config is not None:
+        return
+      self._config = {}
+
+    self._InitializeRecursive(
+        configs=configs, config_files=config_files)
+
+  def _InitializeRecursive(self, configs=None, config_files=None):
+    # This recurses through configs to create temporary files for each and
+    # take advantage of context managers to appropriately close those files.
+    # TODO(jbudorick): Remove this recursion if/when dependency_manager
+    # supports loading configurations directly from a dict.
+    if configs:
+      with tempfile.NamedTemporaryFile() as next_config_file:
+        next_config_file.write(json.dumps(configs[0]))
+        next_config_file.flush()
+        self._InitializeRecursive(
+            configs=configs[1:],
+            config_files=[next_config_file.name] + (config_files or []))
+    else:
+      config_files = config_files or []
+      if 'DEVIL_ENV_CONFIG' in os.environ:
+        config_files.append(os.environ.get('DEVIL_ENV_CONFIG'))
+      config_files.append(_DEVIL_DEFAULT_CONFIG)
+
+      self._dm = dependency_manager.DependencyManager(
+          [dependency_manager.BaseConfig(c) for c in config_files])
+
+  def FetchPath(self, dependency, arch=None, device=None):
+    if self._dm is None:
+      self.Initialize()
+    if dependency in _ANDROID_BUILD_TOOLS:
+      self.FetchPath('android_build_tools_libc++', arch=arch, device=device)
+    return self._dm.FetchPath(dependency, _GetPlatform(arch, device))
+
+  def LocalPath(self, dependency, arch=None, device=None):
+    if self._dm is None:
+      self.Initialize()
+    return self._dm.LocalPath(dependency, _GetPlatform(arch, device))
+
+
+def _GetPlatform(arch, device):
+  if not arch:
+    arch = device.product_cpu_abi if device else 'host'
+  return 'android_%s' % arch
+
+
+config = _Environment()
+