Add dependency_manager initialization to binary_manager

tools/telemetry/telemetry/internal/util/binary_manager.py

 # 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.
 
+#TODO(aiolos): Remove the debug logging once the entire Dependency Manager
+#system has landed.
+import logging
+import os
+
 from catapult_base import support_binaries
+from catapult_base import dependency_manager
+from telemetry.core import exceptions
+from telemetry.core import util
+
+
+TELEMETRY_PROJECT_CONFIG = os.path.join(
+    util.GetTelemetryDir(), 'telemetry', 'internal', 'binary_dependencies.json')
+
+
+_dependency_manager = None
+
+
+def NeedsInit():
+  return not _dependency_manager
+
+
+def InitDependencyManager(environment_config):
+  global _dependency_manager
+  if _dependency_manager:
+    raise exceptions.InitializationError(
+        'Trying to re-initialize the binary manager with config %s'
+        % environment_config)
+  config_files = [TELEMETRY_PROJECT_CONFIG]
+  if environment_config:
+    config_files.append(environment_config)
+  logging.debug('Initializing the dependency manager with config files: %s.'
+                % config_files)
+  _dependency_manager = dependency_manager.DependencyManager(config_files)
+  logging.debug('Successfully initialized the dependency manager.')
 
 
 def FetchPath(binary_name, platform, arch):
   """ Return a path to the appropriate executable for <binary_name>, downloading
       from cloud storage if needed, or None if it cannot be found.
   """
+  logging.debug('Called FetchPath for binary: %s on platform: %s and arch: %s'
+                % (binary_name, platform, arch))
+  if _dependency_manager is None:
+    raise exceptions.InitializationError(
+        'Called FetchPath with uninitialized binary manager.')
   return support_binaries.FindPath(binary_name, platform, arch)
 
+
 def LocalPath(binary_name, platform, arch):
   """ Return a local path to the given binary name, or None if an executable
       cannot be found. Will not download the executable.
       """
+  logging.debug('Called LocalPath for binary: %s on platform: %s and arch: '
+                '%s' % (binary_name, platform, arch))
+  if _dependency_manager is None:
+    raise exceptions.InitializationError(
+        'Called LocalPath with uninitialized binary manager.')
   del platform, arch
   return support_binaries.FindLocallyBuiltPath(binary_name)