[Chromecast] Fix for building Android Cast builds with virtualenv.

build/android/gyp/util/build_utils.py

 # Copyright 2013 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 ast
 import contextlib
 import fnmatch
 import json
 import os
 import pipes
@@ skipping 388 matching lines @@
 
   return sorted_deps
 
 
 def GetPythonDependencies():
   """Gets the paths of imported non-system python modules.
 
   A path is assumed to be a "system" import if it is outside of chromium's
   src/. The paths will be relative to the current directory.
   """
-  module_paths = (m.__file__ for m in sys.modules.itervalues()
-                  if m is not None and hasattr(m, '__file__'))
+  module_paths = GetModulePaths()
 
   abs_module_paths = map(os.path.abspath, module_paths)
 
   assert os.path.isabs(host_paths.DIR_SOURCE_ROOT)
   non_system_module_paths = [
       p for p in abs_module_paths if p.startswith(host_paths.DIR_SOURCE_ROOT)]
   def ConvertPycToPy(s):
     if s.endswith('.pyc'):
       return s[:-1]
     return s
 
   non_system_module_paths = map(ConvertPycToPy, non_system_module_paths)
   non_system_module_paths = map(os.path.relpath, non_system_module_paths)
   return sorted(set(non_system_module_paths))
 
 
+def GetModulePaths():
+  """Returns the paths to all of the modules in sys.modules."""
+  ForceLazyModulesToLoad()
+  return (m.__file__ for m in sys.modules.itervalues()
+          if m is not None and hasattr(m, '__file__'))
+
+
+def ForceLazyModulesToLoad():
+  """Forces any lazily imported modules to fully load themselves.
+
+  Inspecting the modules' __file__ attribute causes lazily imported modules
+  (e.g. from email) to get fully imported and update sys.modules. Iterate
+  over the values until sys.modules stabilizes so that no modules are missed.
+  """
+  while True:
+    num_modules_before = len(sys.modules.keys())
+    for m in sys.modules.values():
+      if m is not None and hasattr(m, '__file__'):
+        _ = m.__file__
+    num_modules_after = len(sys.modules.keys())
+    if num_modules_before == num_modules_after:
+      break
+
+
 def AddDepfileOption(parser):
   # TODO(agrieve): Get rid of this once we've moved to argparse.
   if hasattr(parser, 'add_option'):
     func = parser.add_option
   else:
     func = parser.add_argument
   func('--depfile',
        help='Path to depfile (refer to `gn help depfile`)')
 
 
@@ skipping 110 matching lines @@
 
   md5_check.CallAndRecordIfStale(
       on_stale_md5,
       record_path=record_path,
       input_paths=input_paths,
       input_strings=input_strings,
       output_paths=output_paths,
       force=force,
       pass_changes=True)