Add tracing service and make the shell+sky_viewer+services talk to it

mojo/services/view_manager/view_manager_app.cc

Index: mojo/services/view_manager/view_manager_app.cc
diff --git a/mojo/services/view_manager/view_manager_app.cc b/mojo/services/view_manager/view_manager_app.cc
index 5fa9e110157e8e1c33d867088a567188aad3642d..955c7e27c517b86042fc032eba95b06ac1c8b660 100644
--- a/mojo/services/view_manager/view_manager_app.cc
+++ b/mojo/services/view_manager/view_manager_app.cc
@@ -5,6 +5,7 @@
 #include "mojo/services/view_manager/view_manager_app.h"
 
 #include "mojo/application/application_runner_chromium.h"
+#include "mojo/common/tracing_impl.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_connection.h"
 #include "mojo/public/cpp/application/application_impl.h"
@@ -20,6 +21,10 @@ ViewManagerApp::ViewManagerApp() : wm_app_connection_(nullptr) {
 }
 ViewManagerApp::~ViewManagerApp() {}
 
+void ViewManagerApp::Initialize(ApplicationImpl* app) {
+  TracingImpl::Create(app);
+}
+
 bool ViewManagerApp::ConfigureIncomingConnection(
     ApplicationConnection* connection) {
   if (connection_manager_.get()) {