Refactor/cleanup WebRTC-specific Andorid glue code.

build/android/pylib/constants.py

Index: build/android/pylib/constants.py
diff --git a/build/android/pylib/constants.py b/build/android/pylib/constants.py
index 3d0dfbc941bd2637e9f57e0e9a04d86ea2ac5084..3bf11070df467ef2daee30d1c410cd6eb694398a 100644
--- a/build/android/pylib/constants.py
+++ b/build/android/pylib/constants.py
@@ -11,8 +11,9 @@ import os
 import subprocess
 
 
-DIR_SOURCE_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__),
-                                               os.pardir, os.pardir, os.pardir))
+DIR_SOURCE_ROOT = os.environ.get('CHECKOUT_SOURCE_ROOT',
+    os.path.abspath(os.path.join(os.path.dirname(__file__),
+                                 os.pardir, os.pardir, os.pardir)))
 ISOLATE_DEPS_DIR = os.path.join(DIR_SOURCE_ROOT, 'isolate_deps_dir')
 
 CHROME_SHELL_HOST_DRIVEN_DIR = os.path.join(
@@ -170,7 +171,6 @@ def GetBuildType():
 def SetBuildType(build_type):
   os.environ['BUILDTYPE'] = build_type
 
-
 def GetOutDirectory(build_type=None):
   """Returns the out directory where the output binaries are built.