Refactor net::BackoffEntry to not require subclassing

components/domain_reliability/util.cc

Index: components/domain_reliability/util.cc
diff --git a/components/domain_reliability/util.cc b/components/domain_reliability/util.cc
index 70242aa9ebe0de2e8dd9199afe0b973a2d73d90c..06a8942eaf7a0c8d812f383ae3787ebd5a2e1c14 100644
--- a/components/domain_reliability/util.cc
+++ b/components/domain_reliability/util.cc
@@ -196,17 +196,4 @@ scoped_ptr<MockableTime::Timer> ActualTime::CreateTimer() {
   return scoped_ptr<MockableTime::Timer>(new ActualTimer());
 }
 
-MockableTimeBackoffEntry::MockableTimeBackoffEntry(
-    const net::BackoffEntry::Policy* const policy,
-    MockableTime* time)
-    : net::BackoffEntry(policy),
-      time_(time) {
-}
-
-MockableTimeBackoffEntry::~MockableTimeBackoffEntry() {}
-
-base::TimeTicks MockableTimeBackoffEntry::ImplGetTimeNow() const {
-  return time_->NowTicks();
-}
-
 }  // namespace domain_reliability