Log histograms on shutdown when verbose logging is on

base/metrics/statistics_recorder_unittest.cc

Index: base/metrics/statistics_recorder_unittest.cc
diff --git a/base/metrics/statistics_recorder_unittest.cc b/base/metrics/statistics_recorder_unittest.cc
index 17511a4d4ffa5ea7d57131b743300c08a8708308..ec18afc76212183343494d79fd794cf1f6a9b1ff 100644
--- a/base/metrics/statistics_recorder_unittest.cc
+++ b/base/metrics/statistics_recorder_unittest.cc
@@ -8,6 +8,7 @@
 
 #include "base/bind.h"
 #include "base/json/json_reader.h"
+#include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/histogram_persistence.h"
@@ -61,6 +62,56 @@ class StatisticsRecorderTest : public testing::Test {
   StatisticsRecorder* statistics_recorder_;
 };
 
+// Class to make sure any manipulations we do to the min log level are
+// contained (i.e., do not affect other unit tests).
+class LogStateSaver {

[Alexei Svitkine (slow), 2016/04/14 20:47:39]

Put this in an anon namespace at the top of the file.

+ public:
+  LogStateSaver() : old_min_log_level_(logging::GetMinLogLevel()) {}
+
+  ~LogStateSaver() {
+    logging::SetMinLogLevel(old_min_log_level_);
+    logging::SetLogAssertHandler(nullptr);
+  }
+
+ private:
+  int old_min_log_level_;
+
+  DISALLOW_COPY_AND_ASSIGN(LogStateSaver);
+};
+
+class StatisticsRecorderLoggingTestBase : public StatisticsRecorderTest {
+ protected:
+  void InitLogOnShutdown() {
+    DCHECK(statistics_recorder_);
+    statistics_recorder_->InitLogOnShutdownWithoutLock();
+  }
+
+ private:
+  LogStateSaver log_state_saver_;

[Alexei Svitkine (slow), 2016/04/14 20:47:39]

Is there any problem doing this unconditionally for every test? If so, you can
then remove all these other test classes.

+};
+
+class StatisticsRecorderLoggingWarningOnStartupTest

[Alexei Svitkine (slow), 2016/04/14 20:47:39]

You don't need to create a separate test harness class for each test. Just use
StatisticsRecorderTest.

+    : public StatisticsRecorderLoggingTestBase {
+ protected:
+  void SetUp() override {
+    logging::SetMinLogLevel(logging::LOG_WARNING);
+    StatisticsRecorderLoggingTestBase::SetUp();
+  }
+};
+
+class StatisticsRecorderLoggingVerboseOnStartupTest
+    : public StatisticsRecorderLoggingTestBase {
+ protected:
+  void SetUp() override {
+    logging::SetMinLogLevel(logging::LOG_VERBOSE);
+    StatisticsRecorderTest::SetUp();
+  }
+
+ private:
+  LogStateSaver log_state_saver_;
+};
+
+
 TEST_F(StatisticsRecorderTest, NotInitialized) {
   UninitializeStatisticsRecorder();
 
@@ -513,4 +564,28 @@ TEST_F(StatisticsRecorderTest, CallbackUsedBeforeHistogramCreatedTest) {
   EXPECT_EQ(callback_wrapper.last_histogram_value, 1);
 }
 
+TEST_F(StatisticsRecorderLoggingWarningOnStartupTest,
+       LogOnShutdownNotInitialized) {
+  EXPECT_FALSE(VLOG_IS_ON(1));
+  EXPECT_FALSE(StatisticsRecorder::VLogInitializedForTesting());
+  InitLogOnShutdown();
+  EXPECT_FALSE(StatisticsRecorder::VLogInitializedForTesting());
+}
+
+TEST_F(StatisticsRecorderLoggingWarningOnStartupTest,
+       LogOnShutdownInitializedExplicitly) {
+  EXPECT_FALSE(VLOG_IS_ON(1));
+  EXPECT_FALSE(StatisticsRecorder::VLogInitializedForTesting());
+  logging::SetMinLogLevel(logging::LOG_VERBOSE);
+  EXPECT_TRUE(VLOG_IS_ON(1));
+  InitLogOnShutdown();
+  EXPECT_TRUE(StatisticsRecorder::VLogInitializedForTesting());
+}
+
+TEST_F(StatisticsRecorderLoggingVerboseOnStartupTest,
+       LogOnShutdownInitialized) {
+  EXPECT_TRUE(VLOG_IS_ON(1));
+  EXPECT_TRUE(StatisticsRecorder::VLogInitializedForTesting());
+}
+
 }  // namespace base