Use active state on touch start for tray icons

ash/system/tray/tray_background_view.cc

Index: ash/system/tray/tray_background_view.cc
diff --git a/ash/system/tray/tray_background_view.cc b/ash/system/tray/tray_background_view.cc
index b19b137cfe596d95c38b415745a76a77af585508..a2f602d0a0ced1e207a2a8ce2583e3b1c9ff2992 100644
--- a/ash/system/tray/tray_background_view.cc
+++ b/ash/system/tray/tray_background_view.cc
@@ -17,6 +17,7 @@
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/tray_event_filter.h"
 #include "ash/wm/window_animations.h"
+#include "base/command_line.h"
 #include "grit/ash_resources.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/aura/window.h"
@@ -25,6 +26,7 @@
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animation_element.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/events/event_constants.h"
 #include "ui/gfx/animation/tween.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image_skia.h"
@@ -426,6 +428,20 @@ gfx::Rect TrayBackgroundView::GetFocusBounds() {
   return GetContentsBounds();
 }
 
+void TrayBackgroundView::OnGestureEvent(ui::GestureEvent* event) {
+  if (event->type() == ui::ET_GESTURE_TAP_DOWN &&
+      CommandLine::ForCurrentProcess()->
+          HasSwitch(switches::kAshEnableTouchViewTouchFeedback)) {
+    SetDrawBackgroundAsActive(true);
+  } else if ((event->type() ==  ui::ET_GESTURE_SCROLL_BEGIN ||
+              event->type() ==  ui::ET_GESTURE_TAP_CANCEL) &&
+             CommandLine::ForCurrentProcess()->
+                 HasSwitch(switches::kAshEnableTouchViewTouchFeedback)) {

[Mr4D (OOO till 08-26), 2014/09/04 19:58:35]

CommandLine::ForCurrentProcess()->
    HasSwitch(switches::kAshEnableTouchViewTouchFeedback)

is being used twice here. Since it is in both conditions you might want to check
this only once like

if (commandline..) {
   if (..) {}
   else if {}
}

Furthermore - this is a fixed value throughout the session and touch functions
can get called a lot, so you might consider some pre-parsing

[jonross, 2014/09/05 16:31:49]

Done.

+    SetDrawBackgroundAsActive(false);
+  }
+  ActionableView::OnGestureEvent(event);
+}
+
 void TrayBackgroundView::UpdateBackground(int alpha) {
   // The animator should never fire when the alternate shelf layout is used.
   if (!background_ || draw_background_as_active_)
@@ -628,6 +644,8 @@ TrayBubbleView::AnchorAlignment TrayBackgroundView::GetAnchorAlignment() const {
 }
 
 void TrayBackgroundView::SetDrawBackgroundAsActive(bool visible) {
+  if (draw_background_as_active_ == visible)
+    return;
   draw_background_as_active_ = visible;
   if (!background_)
     return;