Alphabetize list of constructors on global objects

Another consistency fix; prevents spurious changes when moving files
from the Perl list to the Python list (that's why this turned up).
That's the "sorted" in generate_global_constructors_partial_interface,
and the only thing that changes output, namely of
    WindowConstructors.idl
    WorkerGlobalScopeConstructors.idl
...and thus
    V8Window.cpp
    V8WorkerGlobalScope.cpp

Rest of patch is various Python style fixes, esp. list comprehensions.

Review URL: https://chromiumcodereview.appspot.com/22909028

git-svn-id: svn://svn.chromium.org/blink/trunk@156469 bbb929c8-8fbe-4397-9dbb-9b2b20218538