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

build/android/gyp/util/build_utils.py

Index: build/android/gyp/util/build_utils.py
diff --git a/build/android/gyp/util/build_utils.py b/build/android/gyp/util/build_utils.py
index 65bd07b351ca6aaaf65b5f4a8aa050145d99d8f9..53e51ba0c81700ad66008bb7da448a82ac0f8b8e 100644
--- a/build/android/gyp/util/build_utils.py
+++ b/build/android/gyp/util/build_utils.py
@@ -406,7 +406,10 @@ def GetPythonDependencies():
   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()
+  # Don't use sys.modules.itervalues() here. Inspecting the modules causes
+  # lazily imported modules (e.g. from email) to get fully imported and update
+  # sys.modules. This causes a runtime error when iterating with itervalues().
+  module_paths = (m.__file__ for m in sys.modules.values()

[agrieve, 2016/12/14 15:35:28]

If it's being updated during iteration, then we're probably missing some modules
now.

Maybe change this to a loop that exits once the list of modules has stabilized?

                   if m is not None and hasattr(m, '__file__'))
 
   abs_module_paths = map(os.path.abspath, module_paths)