Templatize percentile_filter.h and move it to base/analytics.

webrtc/modules/video_coding/percentile_filter.h

Index: webrtc/modules/video_coding/percentile_filter.h
diff --git a/webrtc/modules/video_coding/percentile_filter.h b/webrtc/modules/video_coding/percentile_filter.h
deleted file mode 100644
index 125a24451553432b4fa1966d091138eb9484fa49..0000000000000000000000000000000000000000
--- a/webrtc/modules/video_coding/percentile_filter.h
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#ifndef WEBRTC_MODULES_VIDEO_CODING_PERCENTILE_FILTER_H_
-#define WEBRTC_MODULES_VIDEO_CODING_PERCENTILE_FILTER_H_
-
-#include <stdint.h>
-
-#include <set>
-
-namespace webrtc {
-
-// Class to efficiently get the percentile value from a group of observations.
-// The percentile is the value below which a given percentage of the
-// observations fall.
-class PercentileFilter {
- public:
-  // Construct filter. |percentile| should be between 0 and 1.
-  explicit PercentileFilter(float percentile);
-
-  // Insert one observation. The complexity of this operation is logarithmic in
-  // the size of the container.
-  void Insert(const int64_t& value);
-  // Remove one observation. The complexity of this operation is logarithmic in
-  // the size of the container.
-  void Erase(const int64_t& value);
-  // Get the percentile value. The complexity of this operation is constant.
-  int64_t GetPercentileValue() const;
-
- private:
-  // Update iterator and index to point at target percentile value.
-  void UpdatePercentileIterator();
-
-  const float percentile_;
-  std::multiset<int64_t> set_;
-  // Maintain iterator and index of current target percentile value.
-  std::multiset<int64_t>::iterator percentile_it_;
-  int64_t percentile_index_;
-};
-
-}  // namespace webrtc
-
-#endif  // WEBRTC_MODULES_VIDEO_CODING_PERCENTILE_FILTER_H_