Fix flaky CountingPolicyTest.CapReturns test

chrome/browser/extensions/activity_log/fullstream_ui_policy_unittest.cc

Index: chrome/browser/extensions/activity_log/fullstream_ui_policy_unittest.cc
diff --git a/chrome/browser/extensions/activity_log/fullstream_ui_policy_unittest.cc b/chrome/browser/extensions/activity_log/fullstream_ui_policy_unittest.cc
index 56e5146b6e37ea060a9556edf8c631bbc5da530f..2502f1ae3008c3f45feede51872f268e70d2f77d 100644
--- a/chrome/browser/extensions/activity_log/fullstream_ui_policy_unittest.cc
+++ b/chrome/browser/extensions/activity_log/fullstream_ui_policy_unittest.cc
@@ -83,7 +83,7 @@ class FullStreamUIPolicyTest : public testing::Test {
     base::CancelableClosure timeout(
         base::Bind(&FullStreamUIPolicyTest::TimeoutCallback));
     base::MessageLoop::current()->PostDelayedTask(
-        FROM_HERE, timeout.callback(), base::TimeDelta::FromSeconds(5));
+        FROM_HERE, timeout.callback(), base::TimeDelta::FromSeconds(8));
 
     // Wait for results; either the checker or the timeout callbacks should
     // cause the main loop to exit.
@@ -659,7 +659,9 @@ TEST_F(FullStreamUIPolicyTest, CapReturns) {
                    base::StringPrintf("apicall_%d", i));
     policy->ProcessAction(action);
   }
+
   policy->Flush();
+  WaitOnThread(BrowserThread::DB);
 
   CheckReadFilteredData(
       policy,