Reporting: Implement garbage collector.

net/reporting/reporting_test_util.cc

Index: net/reporting/reporting_test_util.cc
diff --git a/net/reporting/reporting_test_util.cc b/net/reporting/reporting_test_util.cc
index afc2c274369a82012aa9e0a3ca12e5c17564ff1d..6c23f4185228ef32b6b0e1ce49f38ac5393cdc74 100644
--- a/net/reporting/reporting_test_util.cc
+++ b/net/reporting/reporting_test_util.cc
@@ -13,6 +13,7 @@
 #include "base/memory/ptr_util.h"
 #include "base/test/simple_test_clock.h"
 #include "base/test/simple_test_tick_clock.h"
+#include "base/timer/mock_timer.h"
 #include "net/reporting/reporting_cache.h"
 #include "net/reporting/reporting_client.h"
 #include "net/reporting/reporting_context.h"
@@ -119,9 +120,14 @@ TestReportingContext::TestReportingContext(const ReportingPolicy& policy)
       test_delegate_(new TestReportingDelegate()),
       test_clock_(new base::SimpleTestClock()),
       test_tick_clock_(new base::SimpleTestTickClock()),
+      test_garbage_collection_timer_(
+          new base::MockTimer(/* retain_user_task= */ false,
+                              /* is_repeating= */ false)),
       test_uploader_(new TestReportingUploader()) {
   Init(base::WrapUnique(test_delegate_), base::WrapUnique(test_clock_),
-       base::WrapUnique(test_tick_clock_), base::WrapUnique(test_uploader_));
+       base::WrapUnique(test_tick_clock_),
+       base::WrapUnique(test_garbage_collection_timer_),
+       base::WrapUnique(test_uploader_));
 }
 
 TestReportingContext::~TestReportingContext() {}