GitLab

Split the previous implementation into two pieces:
XmppPushClient and NonBlockingPushClient.

Add FakePushClient and FakePushClientObserver.

Remove use of ThreadSafeObserverList.

Add PushClient::CreateDefault() function, which creates a
NonBlockingPushClient for an XmppPushClient.

Dep-inject PushClient into P2PNotifier.

Add some helper functions to notification_defines.{h,cc}.

BUG=76764
TEST=

Review URL: https://chromiumcodereview.appspot.com/10413014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@138216 0039d316-1c4b-4281-b951-d872f2087c98