Add copy and move constructors to RateStatistics.

Bug: none
Change-Id: I589a7f202ee1c4b8c06e8f44aa570c47d066ab72
Reviewed-on: https://webrtc-review.googlesource.com/95647
Commit-Queue: Sergey Silkin <ssilkin@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24445}

rtc_base/BUILD.gn

@@ -444,6 +444,7 @@ rtc_source_set("rtc_base_approved_generic") {
   deps += [
     "..:webrtc_common",
     "../api:array_view",
+    "//third_party/abseil-cpp/absl/memory:memory",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
 

rtc_base/rate_statistics.cc

@@ -12,6 +12,7 @@
 
 #include <algorithm>
 
+#include "absl/memory/memory.h"
 #include "rtc_base/checks.h"
 
 namespace webrtc {
@@ -26,6 +27,21 @@ RateStatistics::RateStatistics(int64_t window_size_ms, float scale)
       max_window_size_ms_(window_size_ms),
       current_window_size_ms_(max_window_size_ms_) {}
 
+RateStatistics::RateStatistics(const RateStatistics& other)
+    : accumulated_count_(other.accumulated_count_),
+      num_samples_(other.num_samples_),
+      oldest_time_(other.oldest_time_),
+      oldest_index_(other.oldest_index_),
+      scale_(other.scale_),
+      max_window_size_ms_(other.max_window_size_ms_),
+      current_window_size_ms_(other.current_window_size_ms_) {
+  buckets_ = absl::make_unique<Bucket[]>(other.max_window_size_ms_);
+  std::copy(other.buckets_.get(),
+            other.buckets_.get() + other.max_window_size_ms_, buckets_.get());
+}
+
+RateStatistics::RateStatistics(RateStatistics&& other) = default;
+
 RateStatistics::~RateStatistics() {}
 
 void RateStatistics::Reset() {

rtc_base/rate_statistics.h

@@ -27,6 +27,11 @@ class RateStatistics {
   // scale = coefficient to convert counts/ms to desired unit
   //         ex: kBpsScale (8000) for bits/s if count represents bytes.
   RateStatistics(int64_t max_window_size_ms, float scale);
+
+  RateStatistics(const RateStatistics& other);
+
+  RateStatistics(RateStatistics&& other);
+
   ~RateStatistics();
 
   // Reset instance to original state.