Add UMA metrics to measure the effectiveness of views fuzzing

ash/touch/touch_uma.h

Index: ash/touch/touch_uma.h
diff --git a/ash/touch/touch_uma.h b/ash/touch/touch_uma.h
index 46805b10fa0f33dee7bff1a191282936d06df0b0..1a36897375953453345bd9f490def7ec99b3c923 100644
--- a/ash/touch/touch_uma.h
+++ b/ash/touch/touch_uma.h
@@ -8,6 +8,7 @@
 #include <map>
 
 #include "ash/shell.h"
+#include "base/memory/singleton.h"
 #include "ui/gfx/point.h"
 #include "ui/views/widget/widget.h"
 
@@ -20,18 +21,54 @@ namespace internal {
 
 // Records some touch/gesture event specific details (e.g. what gestures are
 // targetted to which components etc.)
-class TouchUMA {
+class ASH_EXPORT TouchUMA {
  public:
-  TouchUMA();
-  ~TouchUMA();
+  enum GestureActionType {
+    GESTURE_UNKNOWN,
+    GESTURE_OMNIBOX_PINCH,
+    GESTURE_OMNIBOX_SCROLL,
+    GESTURE_TABSTRIP_PINCH,
+    GESTURE_TABSTRIP_SCROLL,
+    GESTURE_BEZEL_SCROLL,
+    GESTURE_DESKTOP_SCROLL,
+    GESTURE_DESKTOP_PINCH,
+    GESTURE_WEBPAGE_PINCH,
+    GESTURE_WEBPAGE_SCROLL,
+    GESTURE_WEBPAGE_TAP,
+    GESTURE_TABSTRIP_TAP,
+    GESTURE_BEZEL_DOWN,
+    GESTURE_TABSWITCH_TAP,
+    GESTURE_TABNOSWITCH_TAP,
+    GESTURE_TABCLOSE_TAP,
+    GESTURE_NEWTAB_TAP,
+    GESTURE_FRAMEMAXIMIZE_TAP,
+    GESTURE_FRAMEVIEW_TAP,
+    GESTURE_ROOTVIEWTOP_TAP,
+    GESTURE_MAXIMIZE_DOUBLETAP,
+    // NOTE: Add new action types only immediately above this line. Also,
+    // make sure the enum list in tools/histogram/histograms.xml is
+    // updated with any change in here.
+    GESTURE_ACTION_COUNT
+  };
+
+  // Returns the singleton instance.
+  static TouchUMA* GetInstance();
 
   void RecordGestureEvent(aura::Window* target,
                           const ui::GestureEvent& event);
+  void RecordGestureAction(GestureActionType action);
   void RecordTouchEvent(aura::Window* target,
                         const ui::TouchEvent& event);
 
  private:
+  friend struct DefaultSingletonTraits<TouchUMA>;
+
+  TouchUMA();
+  ~TouchUMA();
+
   void UpdateBurstData(const ui::TouchEvent& event);
+  GestureActionType FindGestureActionType(aura::Window* window,
+                                          const ui::GestureEvent& event);
 
   // These are used to measure the number of touch-start events we receive in a
   // quick succession, regardless of the target window.