Implementing the dispatch of the swipe gesture for one-finger touch swipes.

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 db9f07e1b215e6e33505d995e7a390030d24ee3b..b00255ff9e068467c6feaced33f1c076d2baf869 100644
--- a/ash/touch/touch_uma.cc
+++ b/ash/touch/touch_uma.cc
@@ -44,7 +44,7 @@ enum UMAEventType {
   UMA_ET_GESTURE_PINCH_END,
   UMA_ET_GESTURE_PINCH_UPDATE,
   UMA_ET_GESTURE_LONG_PRESS,
-  UMA_ET_GESTURE_MULTIFINGER_SWIPE,
+  UMA_ET_GESTURE_MULTIFINGER_SWIPE_2,
   UMA_ET_SCROLL,
   UMA_ET_SCROLL_FLING_START,
   UMA_ET_SCROLL_FLING_CANCEL,
@@ -59,6 +59,7 @@ enum UMAEventType {
   UMA_ET_GESTURE_SHOW_PRESS,
   UMA_ET_GESTURE_TAP_CANCEL,
   UMA_ET_GESTURE_WIN8_EDGE_SWIPE,
+  UMA_ET_GESTURE_MULTIFINGER_SWIPE_1,
   // NOTE: Add new event types only immediately above this line. Make sure to
   // update the UIEventType enum in tools/metrics/histograms/histograms.xml
   // accordingly.
@@ -159,14 +160,17 @@ UMAEventType UMAEventTypeFromEvent(const ui::Event& event) {
       return UMA_ET_GESTURE_LONG_PRESS;
     case ui::ET_GESTURE_LONG_TAP:
       return UMA_ET_GESTURE_LONG_TAP;
-    case ui::ET_GESTURE_MULTIFINGER_SWIPE: {
+    case ui::ET_GESTURE_SWIPE: {
       const ui::GestureEvent& gesture =
           static_cast<const ui::GestureEvent&>(event);
       if (gesture.details().touch_points() >= 4)
         return UMA_ET_GESTURE_MULTIFINGER_SWIPE_4P;
       else if (gesture.details().touch_points() == 3)
         return UMA_ET_GESTURE_MULTIFINGER_SWIPE_3;
-      return UMA_ET_GESTURE_MULTIFINGER_SWIPE;
+      else if (gesture.details().touch_points() == 2)
+        return UMA_ET_GESTURE_MULTIFINGER_SWIPE_2;
+      else
+        return UMA_ET_GESTURE_MULTIFINGER_SWIPE_1;

[tdresser, 2014/05/26 20:49:58]

Can we switch to testing in ascending order instead of descending? That way the
most general condition (>= 4) is handled by the else block.

[mfomitchev, 2014/05/26 22:07:14]

Ok. I am going to do the same for UMA_ET_GESTURE_SCROLL_UPDATE then to be
consistent.

     }
     case ui::ET_GESTURE_WIN8_EDGE_SWIPE:
       return UMA_ET_GESTURE_WIN8_EDGE_SWIPE;