Refactor net::BackoffEntry to not require subclassing

Before this patch, net::BackoffEntry had a virtual ImplGetTimeNow method
that tests etc would override to change what time is considered "now".

As suggested by rsleevi in https://codereview.chromium.org/1023473003,
this patch removes that method, and instead makes net::BackoffEntry
accept a base::TickClock in the constructor, to allow overriding the
time without subclassing.

(this will allow future changes to net::BackoffEntry without the
fragile base class problem)

Accordingly, I've removed all subclasses of BackoffEntry, and made them
pass TickClocks instead; in most cases this has been a nice
simplification.

BUG=465399
TBR=stevenjb@chromium.org

Review URL: https://codereview.chromium.org/1076853003

Cr-Commit-Position: refs/heads/master@{#325865}

1 files changed, 2 insertions, 23 deletions

diff --git a/google_apis/gcm/engine/connection_factory_impl_unittest.cc b/google_apis/gcm/engine/connection_factory_impl_unittest.cc
index ed23da9..4c0e127 100644
--- a/google_apis/gcm/engine/connection_factory_impl_unittest.cc
+++ b/google_apis/gcm/engine/connection_factory_impl_unittest.cc
@@ -80,28 +80,6 @@ void ReadContinuation(
 void WriteContinuation() {
 }
 
-class TestBackoffEntry : public net::BackoffEntry {
- public:
-  explicit TestBackoffEntry(base::SimpleTestTickClock* tick_clock);
-  ~TestBackoffEntry() override;
-
-  base::TimeTicks ImplGetTimeNow() const override;
-
- private:
-  base::SimpleTestTickClock* tick_clock_;
-};
-
-TestBackoffEntry::TestBackoffEntry(base::SimpleTestTickClock* tick_clock)
-    : BackoffEntry(&kTestBackoffPolicy),
-      tick_clock_(tick_clock) {
-}
-
-TestBackoffEntry::~TestBackoffEntry() {}
-
-base::TimeTicks TestBackoffEntry::ImplGetTimeNow() const {
-  return tick_clock_->NowTicks();
-}
-
 // A connection factory that stubs out network requests and overrides the
 // backoff policy.
 class TestConnectionFactoryImpl : public ConnectionFactoryImpl {
@@ -213,7 +191,8 @@ void TestConnectionFactoryImpl::InitHandler() {
 
 scoped_ptr<net::BackoffEntry> TestConnectionFactoryImpl::CreateBackoffEntry(
     const net::BackoffEntry::Policy* const policy) {
-  return scoped_ptr<net::BackoffEntry>(new TestBackoffEntry(&tick_clock_));
+  return make_scoped_ptr(new net::BackoffEntry(&kTestBackoffPolicy,
+                                               &tick_clock_));
 }
 
 scoped_ptr<ConnectionHandler>