Refactor net::BackoffEntry to not require subclassing

components/domain_reliability/scheduler.cc

Index: components/domain_reliability/scheduler.cc
diff --git a/components/domain_reliability/scheduler.cc b/components/domain_reliability/scheduler.cc
index d16dfe355edea9e0861356109d52c506b7ed73d0..040c4b1c38a7f1b47ae48a6503928e6720b5204d 100644
--- a/components/domain_reliability/scheduler.cc
+++ b/components/domain_reliability/scheduler.cc
@@ -11,6 +11,7 @@
 #include "base/values.h"
 #include "components/domain_reliability/config.h"
 #include "components/domain_reliability/util.h"
+#include "net/base/backoff_entry.h"
 
 namespace {
 
@@ -92,7 +93,7 @@ DomainReliabilityScheduler::DomainReliabilityScheduler(
 
   for (size_t i = 0; i < num_collectors; ++i) {
     collectors_.push_back(
-      new MockableTimeBackoffEntry(&backoff_policy_, time_));
+      new net::BackoffEntry(&backoff_policy_, time_));
   }
 }