Sync ui/events to chromium @ https://codereview.chromium.org/1210203002

ui/events/ozone/evdev/touch_noise/touch_noise_finder.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/events/ozone/evdev/touch_noise/touch_noise_finder.h"
+
+#include "base/metrics/histogram_macros.h"
+#include "base/stl_util.h"
+#include "ui/events/event_utils.h"
+#include "ui/events/ozone/evdev/touch_noise/far_apart_taps_touch_noise_filter.h"
+#include "ui/events/ozone/evdev/touch_noise/horizontally_aligned_touch_noise_filter.h"
+#include "ui/events/ozone/evdev/touch_noise/single_position_touch_noise_filter.h"
+#include "ui/events/ozone/evdev/touch_noise/touch_noise_filter.h"
+
+namespace ui {
+
+TouchNoiseFinder::TouchNoiseFinder() : last_noise_time_(ui::EventTimeForNow()) {
+  filters_.push_back(new FarApartTapsTouchNoiseFilter);
+  filters_.push_back(new HorizontallyAlignedTouchNoiseFilter);
+  filters_.push_back(new SinglePositionTouchNoiseFilter);
+}
+
+TouchNoiseFinder::~TouchNoiseFinder() {
+  STLDeleteElements(&filters_);
+}
+
+void TouchNoiseFinder::HandleTouches(
+    const std::vector<InProgressTouchEvdev>& touches,
+    base::TimeDelta time) {
+  for (const InProgressTouchEvdev& touch : touches) {
+    if (!touch.was_touching)
+      slots_with_noise_.set(touch.slot, false);
+  }
+
+  bool had_noise = slots_with_noise_.any();
+
+  for (TouchNoiseFilter* filter : filters_)
+    filter->Filter(touches, time, &slots_with_noise_);
+
+  RecordUMA(had_noise, time);
+}
+
+bool TouchNoiseFinder::SlotHasNoise(size_t slot) const {
+  return slots_with_noise_.test(slot);
+}
+
+void TouchNoiseFinder::RecordUMA(bool had_noise, base::TimeDelta time) {
+  if (slots_with_noise_.any()) {
+    if (!had_noise) {
+      UMA_HISTOGRAM_LONG_TIMES(
+          "Ozone.TouchNoiseFilter.TimeSinceLastNoiseOccurrence",
+          time - last_noise_time_);
+    }
+
+    last_noise_time_ = time;
+  }
+}
+
+}  // namespace ui