ash: Add some more touch UMA.

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 ca2a8263baff687c3171970288bd5143ec0105b5..565abe9a300a2044230121fdc8f759a5de2d9808 100644
--- a/ash/touch/touch_uma.cc
+++ b/ash/touch/touch_uma.cc
@@ -267,6 +267,20 @@ void TouchUMA::RecordTouchEvent(aura::Window* target,
     target->SetProperty(kWindowTouchDetails, details);
   }
 
+  // Record the location of the touch points.
+  const int kBucketCount = 100;
+  const gfx::Rect bounds = target->GetRootWindow()->bounds();
+  const int kBucketSizeX = bounds.width() / kBucketCount;
+  const int kBucketSizeY = bounds.height() / kBucketCount;
+  STATIC_HISTOGRAM_POINTER_BLOCK("Ash.TouchPositionX",

[Rick Byers, 2012/08/10 18:07:09]

Too bad there's not a linear version of UMA_HISTOGRAM_COUNTS - I wasn't
expecting you'd need to do the division into buckets yourself, etc..  Oh well.

+      Add(event.root_location().x() / kBucketSizeX),
+      base::LinearHistogram::FactoryGet("Ash.TouchPositionX", 1, kBucketCount,
+          kBucketCount + 1, base::Histogram::kUmaTargetedHistogramFlag));
+  STATIC_HISTOGRAM_POINTER_BLOCK("Ash.TouchPositionY",
+      Add(event.root_location().y() / kBucketSizeY),
+      base::LinearHistogram::FactoryGet("Ash.TouchPositionY", 1, kBucketCount,
+          kBucketCount + 1, base::Histogram::kUmaTargetedHistogramFlag));
+
   if (event.type() == ui::ET_TOUCH_PRESSED) {
     Shell::GetInstance()->delegate()->RecordUserMetricsAction(
         UMA_TOUCHSCREEN_TAP_DOWN);
@@ -286,6 +300,13 @@ void TouchUMA::RecordTouchEvent(aura::Window* target,
             gap.InMilliseconds());
       }
     }
+
+    // Record the number of touch-points currently active for the window.
+    const int kMaxTouchPoints = 10;
+    UMA_HISTOGRAM_CUSTOM_COUNTS("Ash.ActiveTouchPoints",
+        std::min(static_cast<int>(details->last_start_time_.size()),
+                 kMaxTouchPoints),
+        1, kMaxTouchPoints, kMaxTouchPoints);

[sadrul, 2012/08/10 15:54:43]

This will effectively be linear, right?

   } else if (event.type() == ui::ET_TOUCH_RELEASED) {
     if (details->last_start_time_.count(event.touch_id())) {
       base::TimeDelta duration = event.time_stamp() -