Connect SparseHistogram with the rest of stats system

chrome/test/base/uma_histogram_helper.cc

Index: chrome/test/base/uma_histogram_helper.cc
diff --git a/chrome/test/base/uma_histogram_helper.cc b/chrome/test/base/uma_histogram_helper.cc
index 8b4ff416f6e032142675919d487725ed599ae10a..571f477437ddbdae1ab5f91cb738387d3d715e14 100644
--- a/chrome/test/base/uma_histogram_helper.cc
+++ b/chrome/test/base/uma_histogram_helper.cc
@@ -32,8 +32,9 @@ void UMAHistogramHelper::ExpectUniqueSample(
     const std::string& name,
     base::HistogramBase::Sample sample,
     base::HistogramBase::Count expected_count) {
-  base::Histogram* histogram = base::StatisticsRecorder::FindHistogram(name);
-  EXPECT_NE(static_cast<base::Histogram*>(NULL), histogram)
+  base::HistogramBase* histogram =
+      base::StatisticsRecorder::FindHistogram(name);
+  EXPECT_NE(static_cast<base::HistogramBase*>(NULL), histogram)
       << "Histogram \"" << name << "\" does not exist.";
 
   if (histogram) {
@@ -46,8 +47,9 @@ void UMAHistogramHelper::ExpectUniqueSample(
 void UMAHistogramHelper::ExpectTotalCount(
     const std::string& name,
     base::HistogramBase::Count count) {
-  base::Histogram* histogram = base::StatisticsRecorder::FindHistogram(name);
-  EXPECT_NE(static_cast<base::Histogram*>(NULL), histogram)
+  base::HistogramBase* histogram =
+      base::StatisticsRecorder::FindHistogram(name);
+  EXPECT_NE(static_cast<base::HistogramBase*>(NULL), histogram)
       << "Histogram \"" << name << "\" does not exist.";
 
   if (histogram) {