dbus: Stop collecting DBus.RejectedSignalCount histogram

Also, use shorter timeout for SignalSenderVerificationTest.TestSignalRejected
which was disabled because of its slowness.

BUG=407063,643537
TEST=dbus_unittests

Review-Url: https://codereview.chromium.org/2837943004
Cr-Commit-Position: refs/heads/master@{#466912}

dbus/object_proxy.cc

@@ -503,7 +503,6 @@ DBusHandlerResult ObjectProxy::HandleMessage(
   std::string sender = signal->GetSender();
   if (service_name_owner_ != sender) {
     LOG(ERROR) << "Rejecting a message from a wrong sender.";
-    UMA_HISTOGRAM_COUNTS("DBus.RejectedSignalCount", 1);
     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
   }
 

dbus/signal_sender_verification_unittest.cc

@@ -197,27 +197,15 @@ TEST_F(SignalSenderVerificationTest, TestSignalAccepted) {
   ASSERT_EQ(kMessage, test_signal_string_);
 }
 
-// Disabled, http://crbug.com/407063 .
-TEST_F(SignalSenderVerificationTest, DISABLED_TestSignalRejected) {
-  // To make sure the histogram instance is created.
-  UMA_HISTOGRAM_COUNTS("DBus.RejectedSignalCount", 0);
-  base::HistogramBase* reject_signal_histogram =
-        base::StatisticsRecorder::FindHistogram("DBus.RejectedSignalCount");
-  std::unique_ptr<base::HistogramSamples> samples1(
-      reject_signal_histogram->SnapshotSamples());
-
+TEST_F(SignalSenderVerificationTest, TestSignalRejected) {
   const char kNewMessage[] = "hello, new world";
   test_service2_->SendTestSignal(kNewMessage);
 
   // This test tests that our callback is NOT called by the ObjectProxy.
   // Sleep to have message delivered to the client via the D-Bus service.
-  base::PlatformThread::Sleep(TestTimeouts::action_timeout());
-
-  std::unique_ptr<base::HistogramSamples> samples2(
-      reject_signal_histogram->SnapshotSamples());
+  base::PlatformThread::Sleep(TestTimeouts::tiny_timeout());
 
   ASSERT_EQ("", test_signal_string_);
-  EXPECT_EQ(samples1->TotalCount() + 1, samples2->TotalCount());
 }
 
 TEST_F(SignalSenderVerificationTest, TestOwnerChanged) {