Fix Thread race issues and heap corruption in DisplayChannelHost.

Currently, we add deferred messages to a queue in main thread and
handle them in a IO thread. This lead to couple of issues:

1)We are adding to the queue a message in main thread, while
  handling the messages in IO thread.
2)We allocate memory for the queue in main thread(push), while
  we free it in IO thread(pop).

Now, we do so that we post a task to IO thread and all book keeping
happens in IO thread only.

This fixes #169
Gardening: Update to latest revision.

Effecting CLS:
https://codereview.chromium.org/101573006
https://codereview.chromium.org/100213003/
Unify coding style.

Unifies basic coding style across all classes and make cpp lint
happy. All the changes are pretty basic ones. This doesn't handle
any changes which need changes in code(i.e c style casts vs c++),
which need to be handled separately via review process.