Change the FindHistogram interface of StatisticsRecorder

Review URL: https://chromiumcodereview.appspot.com/10802002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@147269 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 59 insertions, 51 deletions

diff --git a/net/disk_cache/stats_histogram.cc b/net/disk_cache/stats_histogram.cc
index 22343d5..66c8e50 100644
--- a/net/disk_cache/stats_histogram.cc
+++ b/net/disk_cache/stats_histogram.cc
@@ -24,15 +24,12 @@ StatsHistogram::~StatsHistogram() {
 }
 
 StatsHistogram* StatsHistogram::FactoryGet(const std::string& name) {
-  Histogram* histogram(NULL);
-
   Sample minimum = 1;
   Sample maximum = disk_cache::Stats::kDataSizesLength - 1;
   size_t bucket_count = disk_cache::Stats::kDataSizesLength;
 
-  if (StatisticsRecorder::FindHistogram(name, &histogram)) {
-    DCHECK(histogram != NULL);
-  } else {
+  Histogram* histogram = StatisticsRecorder::FindHistogram(name);
+  if (!histogram) {
     // To avoid racy destruction at shutdown, the following will be leaked.
     StatsHistogram* stats_histogram =
         new StatsHistogram(name, minimum, maximum, bucket_count);
diff --git a/net/socket_stream/socket_stream_metrics_unittest.cc b/net/socket_stream/socket_stream_metrics_unittest.cc
index e0e11d6..d4daf1e 100644
--- a/net/socket_stream/socket_stream_metrics_unittest.cc
+++ b/net/socket_stream/socket_stream_metrics_unittest.cc
@@ -17,14 +17,13 @@ using base::StatisticsRecorder;
 namespace net {
 
 TEST(SocketStreamMetricsTest, ProtocolType) {
-  Histogram* histogram;
-
   // First we'll preserve the original values. We need to do this
   // as histograms can get affected by other tests. In particular,
   // SocketStreamTest and WebSocketTest can affect the histograms.
   Histogram::SampleSet original;
-  if (StatisticsRecorder::FindHistogram(
-          "Net.SocketStream.ProtocolType", &histogram)) {
+  Histogram* histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.ProtocolType");
+  if (histogram) {
     histogram->SnapshotSample(&original);
   }
 
@@ -35,8 +34,9 @@ TEST(SocketStreamMetricsTest, ProtocolType) {
   SocketStreamMetrics wss2(GURL("wss://www.example.com/"));
   SocketStreamMetrics wss3(GURL("wss://www.example.com/"));
 
-  ASSERT_TRUE(StatisticsRecorder::FindHistogram(
-      "Net.SocketStream.ProtocolType", &histogram));
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.ProtocolType");
+  ASSERT_TRUE(histogram != NULL);
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
 
   Histogram::SampleSet sample;
@@ -49,12 +49,11 @@ TEST(SocketStreamMetricsTest, ProtocolType) {
 }
 
 TEST(SocketStreamMetricsTest, ConnectionType) {
-  Histogram* histogram;
-
   // First we'll preserve the original values.
   Histogram::SampleSet original;
-  if (StatisticsRecorder::FindHistogram(
-          "Net.SocketStream.ConnectionType", &histogram)) {
+  Histogram* histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.ConnectionType");
+  if (histogram) {
     histogram->SnapshotSample(&original);
   }
 
@@ -68,8 +67,10 @@ TEST(SocketStreamMetricsTest, ConnectionType) {
   for (int i = 0; i < 4; ++i)
     metrics.OnCountConnectionType(SocketStreamMetrics::SSL_CONNECTION);
 
-  ASSERT_TRUE(StatisticsRecorder::FindHistogram(
-      "Net.SocketStream.ConnectionType", &histogram));
+
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.ConnectionType");
+  ASSERT_TRUE(histogram != NULL);
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
 
   Histogram::SampleSet sample;
@@ -83,12 +84,11 @@ TEST(SocketStreamMetricsTest, ConnectionType) {
 }
 
 TEST(SocketStreamMetricsTest, WireProtocolType) {
-  Histogram* histogram;
-
   // First we'll preserve the original values.
   Histogram::SampleSet original;
-  if (StatisticsRecorder::FindHistogram(
-          "Net.SocketStream.WireProtocolType", &histogram)) {
+  Histogram* histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.WireProtocolType");
+  if (histogram) {
     histogram->SnapshotSample(&original);
   }
 
@@ -99,8 +99,9 @@ TEST(SocketStreamMetricsTest, WireProtocolType) {
   for (int i = 0; i < 7; ++i)
     metrics.OnCountWireProtocolType(SocketStreamMetrics::WIRE_PROTOCOL_SPDY);
 
-  ASSERT_TRUE(StatisticsRecorder::FindHistogram(
-      "Net.SocketStream.WireProtocolType", &histogram));
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.WireProtocolType");
+  ASSERT_TRUE(histogram != NULL);
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
 
   Histogram::SampleSet sample;
@@ -112,8 +113,6 @@ TEST(SocketStreamMetricsTest, WireProtocolType) {
 }
 
 TEST(SocketStreamMetricsTest, OtherNumbers) {
-  Histogram* histogram;
-
   // First we'll preserve the original values.
   int64 original_received_bytes = 0;
   int64 original_received_counts = 0;
@@ -121,23 +120,28 @@ TEST(SocketStreamMetricsTest, OtherNumbers) {
   int64 original_sent_counts = 0;
 
   Histogram::SampleSet original;
-  if (StatisticsRecorder::FindHistogram(
-          "Net.SocketStream.ReceivedBytes", &histogram)) {
+
+  Histogram* histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.ReceivedBytes");
+  if (histogram) {
     histogram->SnapshotSample(&original);
     original_received_bytes = original.sum();
   }
-  if (StatisticsRecorder::FindHistogram(
-          "Net.SocketStream.ReceivedCounts", &histogram)) {
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.ReceivedCounts");
+  if (histogram) {
     histogram->SnapshotSample(&original);
     original_received_counts = original.sum();
   }
-  if (StatisticsRecorder::FindHistogram(
-          "Net.SocketStream.SentBytes", &histogram)) {
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.SentBytes");
+  if (histogram) {
     histogram->SnapshotSample(&original);
     original_sent_bytes = original.sum();
   }
-  if (StatisticsRecorder::FindHistogram(
-          "Net.SocketStream.SentCounts", &histogram)) {
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.SentCounts");
+  if (histogram) {
     histogram->SnapshotSample(&original);
     original_sent_counts = original.sum();
   }
@@ -156,47 +160,54 @@ TEST(SocketStreamMetricsTest, OtherNumbers) {
   Histogram::SampleSet sample;
 
   // ConnectionLatency.
-  ASSERT_TRUE(StatisticsRecorder::FindHistogram(
-      "Net.SocketStream.ConnectionLatency", &histogram));
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.ConnectionLatency");
+  ASSERT_TRUE(histogram != NULL);
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
   // We don't check the contents of the histogram as it's time sensitive.
 
   // ConnectionEstablish.
-  ASSERT_TRUE(StatisticsRecorder::FindHistogram(
-      "Net.SocketStream.ConnectionEstablish", &histogram));
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.ConnectionEstablish");
+  ASSERT_TRUE(histogram != NULL);
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
   // We don't check the contents of the histogram as it's time sensitive.
 
   // Duration.
-  ASSERT_TRUE(StatisticsRecorder::FindHistogram(
-      "Net.SocketStream.Duration", &histogram));
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.Duration");
+  ASSERT_TRUE(histogram != NULL);
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
   // We don't check the contents of the histogram as it's time sensitive.
 
   // ReceivedBytes.
-  ASSERT_TRUE(StatisticsRecorder::FindHistogram(
-      "Net.SocketStream.ReceivedBytes", &histogram));
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.ReceivedBytes");
+  ASSERT_TRUE(histogram != NULL);
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
   histogram->SnapshotSample(&sample);
   EXPECT_EQ(11, sample.sum() - original_received_bytes);  // 11 bytes read.
 
   // ReceivedCounts.
-  ASSERT_TRUE(StatisticsRecorder::FindHistogram(
-      "Net.SocketStream.ReceivedCounts", &histogram));
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.ReceivedCounts");
+  ASSERT_TRUE(histogram != NULL);
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
   histogram->SnapshotSample(&sample);
   EXPECT_EQ(2, sample.sum() - original_received_counts);  // 2 read requests.
 
   // SentBytes.
-  ASSERT_TRUE(StatisticsRecorder::FindHistogram(
-      "Net.SocketStream.SentBytes", &histogram));
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.SentBytes");
+  ASSERT_TRUE(histogram != NULL);
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
   histogram->SnapshotSample(&sample);
   EXPECT_EQ(222, sample.sum() - original_sent_bytes);  // 222 bytes sent.
 
   // SentCounts.
-  ASSERT_TRUE(StatisticsRecorder::FindHistogram(
-      "Net.SocketStream.SentCounts", &histogram));
+  histogram =
+      StatisticsRecorder::FindHistogram("Net.SocketStream.SentCounts");
+  ASSERT_TRUE(histogram != NULL);
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
   histogram->SnapshotSample(&sample);
   EXPECT_EQ(3, sample.sum() - original_sent_counts);  // 3 write requests.
diff --git a/net/url_request/url_request_throttler_unittest.cc b/net/url_request/url_request_throttler_unittest.cc
index a082779..4721d4c 100644
--- a/net/url_request/url_request_throttler_unittest.cc
+++ b/net/url_request/url_request_throttler_unittest.cc
@@ -208,8 +208,8 @@ void URLRequestThrottlerEntryTest::SetUp() {
     // as other tests may affect them.
     const char* name = kHistogramNames[i];
     Histogram::SampleSet& original = original_samples_[name];
-    Histogram* histogram;
-    if (StatisticsRecorder::FindHistogram(name, &histogram)) {
+    Histogram* histogram = StatisticsRecorder::FindHistogram(name);
+    if (histogram) {
       histogram->SnapshotSample(&original);
     }
   }
@@ -221,8 +221,8 @@ void URLRequestThrottlerEntryTest::CalculateHistogramDeltas() {
     Histogram::SampleSet& original = original_samples_[name];
     Histogram::SampleSet& sample = samples_[name];
 
-    Histogram* histogram;
-    if (StatisticsRecorder::FindHistogram(name, &histogram)) {
+    Histogram* histogram = StatisticsRecorder::FindHistogram(name);
+    if (histogram) {
       ASSERT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
 
       histogram->SnapshotSample(&sample);