[Remoting Android] Fix GetWeakPtr() calls on multiple threads

remoting/client/jni/chromoting_jni_instance.cc

Index: remoting/client/jni/chromoting_jni_instance.cc
diff --git a/remoting/client/jni/chromoting_jni_instance.cc b/remoting/client/jni/chromoting_jni_instance.cc
index de73b4f987abebc957e4a0a8426b5e82579b405d..97f6693f0674066e881d8cf5b7e412465252b412 100644
--- a/remoting/client/jni/chromoting_jni_instance.cc
+++ b/remoting/client/jni/chromoting_jni_instance.cc
@@ -74,6 +74,7 @@ ChromotingJniInstance::ChromotingJniInstance(
       capabilities_(capabilities),
       weak_factory_(this) {
   DCHECK(jni_runtime_->ui_task_runner()->BelongsToCurrentThread());
+  weak_ptr_ = weak_factory_.GetWeakPtr();
 
   // Initialize XMPP config.
   xmpp_config_.host = kXmppServer;
@@ -369,7 +370,7 @@ void ChromotingJniInstance::InjectClipboardEvent(
 }
 
 base::WeakPtr<ChromotingJniInstance> ChromotingJniInstance::GetWeakPtr() {
-  return weak_factory_.GetWeakPtr();
+  return weak_ptr_;
 }
 
 void ChromotingJniInstance::ConnectToHostOnNetworkThread() {