Added UMA statistics for changing the active window via click or touch events.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index fb61b55893a6e7c274829105a75bea1f9966b97d..502f6711a36b47b4cd47b6777052781ba28a627b 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -660,6 +660,8 @@ Shell::Shell(ShellDelegate* delegate)
 Shell::~Shell() {
   TRACE_EVENT0("shutdown", "ash::Shell::Destructor");
 
+  user_metrics_recorder_->OnShellShuttingDown();
+
   delegate_->PreShutdown();
 
   views::FocusManagerFactory::Install(NULL);
@@ -1085,6 +1087,8 @@ void Shell::Init(const ShellInitParams& init_params) {
   // order to create mirror window. Run it after the main message loop
   // is started.
   display_manager_->CreateMirrorWindowAsyncIfAny();
+
+  user_metrics_recorder_->OnShellInitialized();
 }
 
 void Shell::InitKeyboard() {
@@ -1177,8 +1181,10 @@ void Shell::OnEvent(ui::Event* event) {
 ////////////////////////////////////////////////////////////////////////////////
 // Shell, aura::client::ActivationChangeObserver implementation:
 
-void Shell::OnWindowActivated(aura::Window* gained_active,
-                              aura::Window* lost_active) {
+void Shell::OnWindowActivated(
+    aura::client::ActivationChangeObserver::ActivationReason reason,
+    aura::Window* gained_active,
+    aura::Window* lost_active) {
   if (gained_active)
     target_root_window_ = gained_active->GetRootWindow();
 }