Add fade to white animation when power button is pressed on Athena

athena/system/power_button_controller.cc

Index: athena/system/power_button_controller.cc
diff --git a/athena/system/power_button_controller.cc b/athena/system/power_button_controller.cc
index c54ca46419af9bc7481d2a02ec9f42e08ee8942d..bcafa1c61a45f6f35d699ed91927f8d6e1583704 100644
--- a/athena/system/power_button_controller.cc
+++ b/athena/system/power_button_controller.cc
@@ -4,13 +4,16 @@
 
 #include "athena/system/power_button_controller.h"
 
+#include "athena/screen/public/screen_animator.h"
+#include "athena/screen/public/screen_manager.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 
 namespace athena {
 
 PowerButtonController::PowerButtonController()
-    : brightness_is_zero_(false),
-      shutdown_requested_(false) {
+    : animator_(ScreenManager::Get()->CreateScreenAnimator()),
+      brightness_is_zero_(false),
+      state_(STATE_OTHER) {
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(
       this);
 }
@@ -28,7 +31,7 @@ void PowerButtonController::BrightnessChanged(int level, bool user_initiated) {
 
 void PowerButtonController::PowerButtonEventReceived(
     bool down,
-    const base::TimeTicks& details) {
+    const base::TimeTicks& timestamp) {
   // Avoid requesting a shutdown if the power button is pressed while the screen
   // is off (http://crbug.com/128451)
   base::TimeDelta time_since_zero_brightness = brightness_is_zero_ ?
@@ -37,12 +40,25 @@ void PowerButtonController::PowerButtonEventReceived(
   if (time_since_zero_brightness.InMilliseconds() <= kShortTimeMs)
     return;
 
-  if (down && !shutdown_requested_) {
-    shutdown_requested_ = true;
-    chromeos::DBusThreadManager::Get()
-        ->GetPowerManagerClient()
-        ->RequestShutdown();
+  if (state_ == STATE_SHUTDOWN_REQUESTED)
+    return;
+
+  StopObservingImplicitAnimations();
+  if (down) {
+    state_ = STATE_PRE_SHUTDOWN_ANIMATION;
+    animator_->StartAnimation(ScreenAnimator::ANIMATION_SHUTDOWN, this);
+  } else {
+    state_ = STATE_OTHER;
+    animator_->StartAnimation(ScreenAnimator::ANIMATION_CANCEL_SHUTDOWN, NULL);
   }
 }
 
+void PowerButtonController::OnImplicitAnimationsCompleted() {
+  DCHECK_EQ(STATE_PRE_SHUTDOWN_ANIMATION, state_);
+  state_ = STATE_SHUTDOWN_REQUESTED;
+  chromeos::DBusThreadManager::Get()
+      ->GetPowerManagerClient()
+      ->RequestShutdown();
+}
+
 }  // namespace athena