ash: Add some UMA for touch-events.

ash/wm/system_gesture_event_filter.cc

Index: ash/wm/system_gesture_event_filter.cc
diff --git a/ash/wm/system_gesture_event_filter.cc b/ash/wm/system_gesture_event_filter.cc
index 34ee6e442e9e991c451d46680a583563a8782f15..15fa798b7f128524c1db36b0c456a471ddc382dc 100644
--- a/ash/wm/system_gesture_event_filter.cc
+++ b/ash/wm/system_gesture_event_filter.cc
@@ -10,6 +10,7 @@
 #include "ash/root_window_controller.h"
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
+#include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/brightness/brightness_control_delegate.h"
 #include "ash/volume_control_delegate.h"
@@ -38,6 +39,10 @@
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_delegate.h"
 
+#if defined(OS_CHROMEOS)
+#include "ui/base/touch/touch_factory.h"
+#endif
+
 namespace {
 using views::Widget;
 
@@ -527,6 +532,14 @@ bool SystemGestureEventFilter::PreHandleKeyEvent(aura::Window* target,
 
 bool SystemGestureEventFilter::PreHandleMouseEvent(aura::Window* target,
                                                    aura::MouseEvent* event) {
+#if defined(OS_CHROMEOS)
+  if (event->type() == ui::ET_MOUSE_PRESSED && event->native_event() &&
+      ui::TouchFactory::GetInstance()->IsTouchDevicePresent() &&
+      ui::IsTouchpadEvent(event->native_event())) {

[Rick Byers, 2012/07/31 20:37:36]

I don't think we need to restrict ourselves to touchpad events here.  If a user
has an external / bluetooth mouse, it would be good to include those events in
our metric as well.  Alternately it would be nice to report TOUCHPAD_TAP_DOWN
separately from MOUSE_TAP_DOWN but I'm not sure the distinction has much
value...

[sadrul, 2012/08/01 16:15:27]

Done (using just MOUSE_DOWN for both mouse/touchpad)

+    Shell::GetInstance()->delegate()->RecordUserMetricsAction(
+      UMA_TOUCHPAD_TAP_DOWN);
+  }
+#endif
   return false;
 }