Allow backoff entry serialization if clock is null.

net/base/backoff_entry_serializer.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/base/backoff_entry_serializer.h"
 
 #include <utility>
 
 #include "base/strings/string_number_conversions.h"
 #include "base/time/tick_clock.h"
@@ skipping 11 matching lines @@
 std::unique_ptr<base::Value> BackoffEntrySerializer::SerializeToValue(
     const BackoffEntry& entry,
     base::Time time_now) {
   std::unique_ptr<base::ListValue> serialized(new base::ListValue());
   serialized->AppendInteger(kSerializationFormatVersion);
 
   serialized->AppendInteger(entry.failure_count());
 
   // Can't use entry.GetTimeUntilRelease as it doesn't allow negative deltas.
   base::TimeDelta backoff_duration =
-      entry.GetReleaseTime() - entry.tick_clock()->NowTicks();

[johnme, 2016/10/03 12:18:22]

I believe this is the only caller of tick_clock(). Please remove the method as
well.

[Olivier, 2016/10/03 12:29:24]

Done.

+      entry.GetReleaseTime() - entry.GetTimeTicksNow();
   // Redundantly stores both the remaining time delta and the absolute time.
   // The delta is used to work around some cases where wall clock time changes.
   serialized->AppendDouble(backoff_duration.InSecondsF());
   base::Time absolute_release_time = backoff_duration + time_now;
   serialized->AppendString(
       base::Int64ToString(absolute_release_time.ToInternalValue()));
 
   return std::move(serialized);
 }
 
@@ skipping 45 matching lines @@
   // against the clock being wound forward).
   if (backoff_duration > original_backoff_duration)
     backoff_duration = original_backoff_duration;
   entry->SetCustomReleaseTime(
       entry->BackoffDurationToReleaseTime(backoff_duration));
 
   return entry;
 }
 
 }  // namespace net