[Sync] Turn notifier::PushClient into an interface

jingle/jingle.gyp

Index: jingle/jingle.gyp
diff --git a/jingle/jingle.gyp b/jingle/jingle.gyp
index 9f9af8b3b5032fb1e7a640fbdc74c51b41ef2243..3d424a0369d936487f735b09f25149e5bfceb2a8 100644
--- a/jingle/jingle.gyp
+++ b/jingle/jingle.gyp
@@ -75,12 +75,16 @@
         'notifier/communicator/login_settings.h',
         'notifier/communicator/single_login_attempt.cc',
         'notifier/communicator/single_login_attempt.h',
-        'notifier/listener/push_client.cc',
-        'notifier/listener/push_client.h',
+        'notifier/listener/non_blocking_push_client.cc',
+        'notifier/listener/non_blocking_push_client.h',
         'notifier/listener/notification_constants.cc',
         'notifier/listener/notification_constants.h',
         'notifier/listener/notification_defines.cc',
         'notifier/listener/notification_defines.h',
+        'notifier/listener/push_client_observer.cc',
+        'notifier/listener/push_client_observer.h',
+        'notifier/listener/push_client.cc',
+        'notifier/listener/push_client.h',
         'notifier/listener/push_notifications_listen_task.cc',
         'notifier/listener/push_notifications_listen_task.h',
         'notifier/listener/push_notifications_send_update_task.cc',
@@ -89,6 +93,8 @@
         'notifier/listener/push_notifications_subscribe_task.h',
         'notifier/listener/xml_element_util.cc',
         'notifier/listener/xml_element_util.h',
+        'notifier/listener/xmpp_push_client.cc',
+        'notifier/listener/xmpp_push_client.h',
       ],
       'defines' : [
         '_CRT_SECURE_NO_WARNINGS',
@@ -120,6 +126,10 @@
         'notifier/base/fake_base_task.h',
         'notifier/base/mock_task.cc',
         'notifier/base/mock_task.h',
+        'notifier/listener/fake_push_client.cc',
+        'notifier/listener/fake_push_client.h',
+        'notifier/listener/fake_push_client_observer.cc',
+        'notifier/listener/fake_push_client_observer.h',
       ],
       'dependencies': [
         'notifier',
@@ -160,10 +170,12 @@
         'notifier/communicator/connection_settings_unittest.cc',
         'notifier/communicator/login_settings_unittest.cc',
         'notifier/communicator/single_login_attempt_unittest.cc',
+        'notifier/listener/non_blocking_push_client_unittest.cc',
         'notifier/listener/push_client_unittest.cc',
         'notifier/listener/push_notifications_send_update_task_unittest.cc',
         'notifier/listener/push_notifications_subscribe_task_unittest.cc',
         'notifier/listener/xml_element_util_unittest.cc',
+        'notifier/listener/xmpp_push_client_unittest.cc',
         'run_all_unittests.cc',
       ],
       'conditions': [