Connect SparseHistogram with the rest of stats system

net/url_request/url_request_throttler_unittest.cc

Index: net/url_request/url_request_throttler_unittest.cc
diff --git a/net/url_request/url_request_throttler_unittest.cc b/net/url_request/url_request_throttler_unittest.cc
index 998fb064b6dd8c460cca4400823ca74b4e33fcbc..bb010c385b1043dc2a5709d1d3a8154f83b2ab04 100644
--- a/net/url_request/url_request_throttler_unittest.cc
+++ b/net/url_request/url_request_throttler_unittest.cc
@@ -29,6 +29,7 @@ namespace net {
 namespace {
 
 using base::Histogram;
+using base::HistogramBase;
 using base::HistogramSamples;
 using base::StatisticsRecorder;
 
@@ -211,7 +212,7 @@ void URLRequestThrottlerEntryTest::SetUp() {
     // Must retrieve original samples for each histogram for comparison
     // as other tests may affect them.
     const char* name = kHistogramNames[i];
-    Histogram* histogram = StatisticsRecorder::FindHistogram(name);
+    HistogramBase* histogram = StatisticsRecorder::FindHistogram(name);
     if (histogram) {
       original_samples_[name] = histogram->SnapshotSamples().release();
     } else {
@@ -230,9 +231,9 @@ void URLRequestThrottlerEntryTest::CalculateHistogramDeltas() {
     const char* name = kHistogramNames[i];
     HistogramSamples* original = original_samples_[name];
 
-    Histogram* histogram = StatisticsRecorder::FindHistogram(name);
+    HistogramBase* histogram = StatisticsRecorder::FindHistogram(name);
     if (histogram) {
-      ASSERT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
+      ASSERT_EQ(HistogramBase::kUmaTargetedHistogramFlag, histogram->flags());
 
       scoped_ptr<HistogramSamples> samples(histogram->SnapshotSamples());
       if (original)