ash: Add some UMA for touch-events.

ash/touch/touch_uma.cc

Index: ash/touch/touch_uma.cc
diff --git a/ash/touch/touch_uma.cc b/ash/touch/touch_uma.cc
index 9438cce762e8c2ce50bbaf9c6b16fae883d81c13..190d08a717cf44fd9ddd9fb0788aa157445d4509 100644
--- a/ash/touch/touch_uma.cc
+++ b/ash/touch/touch_uma.cc
@@ -4,6 +4,7 @@
 
 #include "ash/touch/touch_uma.h"
 
+#include "ash/shell_delegate.h"
 #include "base/metrics/histogram.h"
 #include "base/stringprintf.h"
 #include "ui/aura/event.h"
@@ -224,7 +225,14 @@ void TouchUMA::RecordGestureEvent(aura::Window* target,
 
 void TouchUMA::RecordTouchEvent(aura::Window* target,
                                 const aura::TouchEvent& event) {
-  // TODO(sad|rjkroege): Figure out what to do (heat map?).
+  if (event.type() == ui::ET_TOUCH_PRESSED) {
+    Shell::GetInstance()->delegate()->RecordUserMetricsAction(
+        UMA_TOUCHSCREEN_TAP_DOWN);
+  }
+
+  UMA_HISTOGRAM_CUSTOM_COUNTS("Ash.TouchRadius",
+      static_cast<int>(std::max(event.radius_x(), event.radius_y())),
+      1, 500, 100);

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

This seems reasonable to me.  We've seen radii > 500 on some devices with buggy
firmware, but it looks like that'll just go into the overflow bucket.  

 }
 
 }  // namespace internal