Extensions: Fix DocServer assert failures.

chrome/common/extensions/docs/server2/api_schema_graph.py

Index: chrome/common/extensions/docs/server2/api_schema_graph.py
diff --git a/chrome/common/extensions/docs/server2/api_schema_graph.py b/chrome/common/extensions/docs/server2/api_schema_graph.py
index 0c90ba1d9afa4ee238316ac9ed8f6447fd8e65c5..008b397dd35a3b41b5174d7996e637368d11c40a 100644
--- a/chrome/common/extensions/docs/server2/api_schema_graph.py
+++ b/chrome/common/extensions/docs/server2/api_schema_graph.py
@@ -80,7 +80,8 @@ class APINodeCursor(object):
       if self._lookup_path[-1] == 'callback':
         # This is an event callback, so lookup_path[-2] is the event
         # node name, thus lookup_path[-3] must be 'events'.
-        assert self._lookup_path[-3] == 'events'
+        assert self._lookup_path[-3] == 'events' , 'Invalid lookup path- %s' \

[Devlin, 2017/03/13 20:38:18]

nitty nit: Let's separate the lines so the error string is together:
assert self._lookup_path[-3] == 'events' , \
    'Invalid lookup path: %s' % (self._lookup_path)

Also, let's replace the '-' with a ':' (which is a little more common).

[karandeepb, 2017/03/14 01:02:02]

Done. Again is there a formatter commonly used for chromium python code?

[Devlin, 2017/03/14 01:12:05]

No formatter I'm aware of.  I think there are some tools that probably do "a
decent job", but nothing canonical.

+            % (self._lookup_path)
         return self._lookup_path[:-1]
       # This is a function parameter.
       assert self._lookup_path[-2] == 'parameters'