Merge histograms from providers into StatisticsRecorder for display.

components/metrics/metrics_provider.cc

Index: components/metrics/metrics_provider.cc
diff --git a/components/metrics/metrics_provider.cc b/components/metrics/metrics_provider.cc
index 50f621a73ec9973be4d4dabe248c21c1b8dadb94..fd864e41136ebaa916cc16496777de8fbc970a59 100644
--- a/components/metrics/metrics_provider.cc
+++ b/components/metrics/metrics_provider.cc
@@ -50,9 +50,6 @@ void MetricsProvider::ProvideGeneralMetrics(
     ChromeUserMetricsExtension* uma_proto) {
 }
 
-void MetricsProvider::MergeHistogramDeltas() {
-}
-
 void MetricsProvider::RecordHistogramSnapshots(
     base::HistogramSnapshotManager* snapshot_manager) {
 }