Add the request picker and a unit test

components/offline_pages/background/request_coordinator_unittest.cc

Index: components/offline_pages/background/request_coordinator_unittest.cc
diff --git a/components/offline_pages/background/request_coordinator_unittest.cc b/components/offline_pages/background/request_coordinator_unittest.cc
index ab506f0aab026eeacf09e13283d31e26ba100f8b..28bbf2155203472a5ea1d4e7b97f65519923e85d 100644
--- a/components/offline_pages/background/request_coordinator_unittest.cc
+++ b/components/offline_pages/background/request_coordinator_unittest.cc
@@ -172,12 +172,6 @@ TEST_F(RequestCoordinatorTest, SavePageLater) {
   SchedulerStub* scheduler_stub = reinterpret_cast<SchedulerStub*>(
       coordinator()->GetSchedulerForTesting());
   EXPECT_TRUE(scheduler_stub->schedule_called());
-
-  // Check that the offliner callback got a response.
-  EXPECT_EQ(Offliner::RequestStatus::SAVED,
-            coordinator()->last_offlining_status());
-
-  // TODO(petewil): Expect that the scheduler got notified.
 }
 
 }  // namespace offline_pages