[Android] Sever findbugs dependencies on environment variables.

build/android/findbugs_diff.py

Index: build/android/findbugs_diff.py
diff --git a/build/android/findbugs_diff.py b/build/android/findbugs_diff.py
index eb49824ef2375c1c013a31ea607a8da4cb55b8a2..4dc67428ee61d2e6bbb49105cff03fa3120e0e16 100755
--- a/build/android/findbugs_diff.py
+++ b/build/android/findbugs_diff.py
@@ -28,21 +28,17 @@ import optparse
 import os
 import sys
 
-from pylib import findbugs
+from pylib import constants
+from pylib.utils import findbugs
 
 
 def main(argv):
-  if not findbugs.CheckEnvironment():
-    return 1
-
   parser = findbugs.GetCommonParser()
 
   options, _ = parser.parse_args()
 
-  chrome_src = os.getenv('CHROME_SRC')
-
   if not options.base_dir:
-    options.base_dir = os.path.join(chrome_src, 'build', 'android',
+    options.base_dir = os.path.join(constants.CHROME_DIR, 'build', 'android',
                                     'findbugs_filter')
   if not options.only_analyze:
     options.only_analyze = 'org.chromium.-'