Revert "Delete legacy DataSize and DataRate factories"

This reverts commit 70490aa3a0b08c9342ea9a12d5ac1fa9666fb7fb.

Reason for revert: Breaks downstream project.

Original change's description:
> Delete legacy DataSize and DataRate factories
> 
> Bug: webrtc:9709
> Change-Id: Ia9464893ec9868c51d72eedaee8efc82b0c17b28
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/168722
> Reviewed-by: Sebastian Jansson <srte@webrtc.org>
> Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#30564}

TBR=danilchap@webrtc.org,srte@webrtc.org

Change-Id: I3f5a8b4ec473bd2af80ca3acfe0e9c82f25a12ba
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9709
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/168940
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30574}

api/units/data_rate.h

@@ -49,7 +49,31 @@ class DataRate final : public rtc_units_impl::RelativeUnit<DataRate> {
   static constexpr DataRate Infinity() { return PlusInfinity(); }
 
   DataRate() = delete;
-
+  // TODO(danilchap): Migrate all code to the 3 factories above and delete the
+  // 5 factories below.
+  template <int64_t bps>
+  static constexpr DataRate BitsPerSec() {
+    return FromValue(bps);
+  }
+  template <int64_t kbps>
+  static constexpr DataRate KilobitsPerSec() {
+    return FromFraction(1000, kbps);
+  }
+  template <typename T>
+  static constexpr DataRate bps(T bits_per_second) {
+    static_assert(std::is_arithmetic<T>::value, "");
+    return FromValue(bits_per_second);
+  }
+  template <typename T>
+  static constexpr DataRate bytes_per_sec(T bytes_per_second) {
+    static_assert(std::is_arithmetic<T>::value, "");
+    return FromFraction(8, bytes_per_second);
+  }
+  template <typename T>
+  static constexpr DataRate kbps(T kilobits_per_sec) {
+    static_assert(std::is_arithmetic<T>::value, "");
+    return FromFraction(1000, kilobits_per_sec);
+  }
   template <typename T = int64_t>
   constexpr T bps() const {
     return ToValue<T>();

api/units/data_size.h

@@ -32,7 +32,18 @@ class DataSize final : public rtc_units_impl::RelativeUnit<DataSize> {
   static constexpr DataSize Infinity() { return PlusInfinity(); }
 
   DataSize() = delete;
+  // TODO(danilchap): Migrate all code to the factory above and delete the
+  // 2 factories below.
+  template <int64_t bytes>
+  static constexpr DataSize Bytes() {
+    return FromValue(bytes);
+  }
 
+  template <typename T>
+  static constexpr DataSize bytes(T bytes) {
+    static_assert(std::is_arithmetic<T>::value, "");
+    return FromValue(bytes);
+  }
   template <typename T = int64_t>
   constexpr T bytes() const {
     return ToValue<T>();

modules/congestion_controller/pcc/pcc_network_controller.cc

@@ -32,8 +32,9 @@ constexpr int64_t kMinPacketsNumberPerInterval = 20;
 const TimeDelta kMinDurationOfMonitorInterval = TimeDelta::Millis(50);
 const TimeDelta kStartupDuration = TimeDelta::Millis(500);
 constexpr double kMinRateChangeBps = 4000;
-constexpr DataRate kMinRateHaveMultiplicativeRateChange = DataRate::BitsPerSec(
-    static_cast<int64_t>(kMinRateChangeBps / kDefaultSamplingStep));
+constexpr DataRate kMinRateHaveMultiplicativeRateChange =
+    DataRate::BitsPerSec<static_cast<int64_t>(kMinRateChangeBps /
+                                              kDefaultSamplingStep)>();
 
 // Bitrate controller constants.
 constexpr double kInitialConversionFactor = 5;