Replace includes of webrtc/base/task.h and taskparent.h.

BUG=webrtc:6424

Review-Url: https://codereview.chromium.org/2737133002
Cr-Commit-Position: refs/heads/master@{#455698}

third_party/libjingle_xmpp/xmpp/xmppclient.h

@@ -14,12 +14,12 @@
 #include <memory>
 #include <string>
 
+#include "third_party/libjingle_xmpp/task_runner/task.h"
 #include "third_party/libjingle_xmpp/xmpp/asyncsocket.h"
 #include "third_party/libjingle_xmpp/xmpp/xmppclientsettings.h"
 #include "third_party/libjingle_xmpp/xmpp/xmppengine.h"
 #include "third_party/libjingle_xmpp/xmpp/xmpptask.h"
 #include "third_party/webrtc/base/sigslot.h"
-#include "third_party/webrtc/base/task.h"
 
 namespace buzz {
 

third_party/libjingle_xmpp/xmpp/xmpptask.h

@@ -15,11 +15,11 @@
 #include <memory>
 #include <string>
 
+#include "third_party/libjingle_xmpp/task_runner/task.h"
+#include "third_party/libjingle_xmpp/task_runner/taskparent.h"
 #include "third_party/libjingle_xmpp/xmpp/xmppengine.h"
 #include "third_party/webrtc/base/constructormagic.h"
 #include "third_party/webrtc/base/sigslot.h"
-#include "third_party/webrtc/base/task.h"
-#include "third_party/webrtc/base/taskparent.h"
 
 namespace buzz {