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

ui/wm/core/focus_controller.cc

Index: ui/wm/core/focus_controller.cc
diff --git a/ui/wm/core/focus_controller.cc b/ui/wm/core/focus_controller.cc
index 446e82c269fc4e852491886d1207ecfeaddc93cf..f1955d073945c792cbc05cdf4c359c61bf3b8e11 100644
--- a/ui/wm/core/focus_controller.cc
+++ b/ui/wm/core/focus_controller.cc
@@ -103,6 +103,14 @@ void FocusController::RemoveObserver(
 }
 
 void FocusController::FocusWindow(aura::Window* window) {
+  FocusWindowImpl(aura::client::ActivationChangeObserver::ActivationReason::
+                      kActivationClient,
+                  window);
+}
+
+void FocusController::FocusWindowImpl(
+    aura::client::ActivationChangeObserver::ActivationReason reason,
+    aura::Window* window) {
   if (window &&
       (window->Contains(focused_window_) || window->Contains(active_window_))) {
     return;
@@ -125,7 +133,7 @@ void FocusController::FocusWindow(aura::Window* window) {
   // we must not adjust the focus below since this will clobber that change.
   aura::Window* last_focused_window = focused_window_;
   if (!updating_activation_)
-    SetActiveWindow(window, activatable);
+    SetActiveWindow(reason, window, activatable);
 
   // If the window's ActivationChangeObserver shifted focus to a valid window,
   // we don't want to focus the window we thought would be focused by default.
@@ -268,8 +276,10 @@ void FocusController::SetFocusedWindow(aura::Window* window) {
     text_input_focus_manager->FocusTextInputClient(NULL);
 }
 
-void FocusController::SetActiveWindow(aura::Window* requested_window,
-                                      aura::Window* window) {
+void FocusController::SetActiveWindow(
+    aura::client::ActivationChangeObserver::ActivationReason reason,
+    aura::Window* requested_window,
+    aura::Window* window) {
   if (updating_activation_)
     return;
 
@@ -310,19 +320,19 @@ void FocusController::SetActiveWindow(aura::Window* requested_window,
   if (window_tracker.Contains(lost_activation)) {
     observer = aura::client::GetActivationChangeObserver(lost_activation);
     if (observer)
-      observer->OnWindowActivated(active_window_, lost_activation);
+      observer->OnWindowActivated(reason, active_window_, lost_activation);
   }
   observer = aura::client::GetActivationChangeObserver(active_window_);
   if (observer) {
     observer->OnWindowActivated(
-        active_window_,
+        reason, active_window_,
         window_tracker.Contains(lost_activation) ? lost_activation : NULL);
   }
-  FOR_EACH_OBSERVER(aura::client::ActivationChangeObserver,
-                    activation_observers_,
-                    OnWindowActivated(active_window_,
-                                      window_tracker.Contains(lost_activation) ?
-                                      lost_activation : NULL));
+  FOR_EACH_OBSERVER(
+      aura::client::ActivationChangeObserver, activation_observers_,
+      OnWindowActivated(
+          reason, active_window_,
+          window_tracker.Contains(lost_activation) ? lost_activation : NULL));
 }
 
 void FocusController::WindowLostFocusFromDispositionChange(
@@ -335,7 +345,9 @@ void FocusController::WindowLostFocusFromDispositionChange(
   // that process so there's no point in updating focus independently.
   if (window == active_window_) {
     aura::Window* next_activatable = rules_->GetNextActivatableWindow(window);
-    SetActiveWindow(NULL, next_activatable);
+    SetActiveWindow(aura::client::ActivationChangeObserver::ActivationReason::
+                        kWindowDispositionChanged,
+                    NULL, next_activatable);
     if (!(active_window_ && active_window_->Contains(focused_window_)))
       SetFocusedWindow(next_activatable);
   } else if (window->Contains(focused_window_)) {
@@ -348,8 +360,11 @@ void FocusController::WindowFocusedFromInputEvent(aura::Window* window) {
   // Only focus |window| if it or any of its parents can be focused. Otherwise
   // FocusWindow() will focus the topmost window, which may not be the
   // currently focused one.
-  if (rules_->CanFocusWindow(GetToplevelWindow(window)))
-    FocusWindow(window);
+  if (rules_->CanFocusWindow(GetToplevelWindow(window))) {
+    FocusWindowImpl(
+        aura::client::ActivationChangeObserver::ActivationReason::kInputEvent,
+        window);
+  }
 }
 
 }  // namespace wm