Measuring data use of different ModelTypes in Sync Service.

net/url_request/data_use_measurement.cc

Index: net/url_request/data_use_measurement.cc
diff --git a/net/url_request/data_use_measurement.cc b/net/url_request/data_use_measurement.cc
index d27cc1b397e084f9ea9d8f086d01ffba4a6c2426..70b075455756db4e529f6f4ba27e31864bfb7458 100644
--- a/net/url_request/data_use_measurement.cc
+++ b/net/url_request/data_use_measurement.cc
@@ -136,6 +136,13 @@ void ReportDataUsage(const std::string& service_name,
 
 }  // namespace
 
+void SparseDataUseReport(const std::string& histogram_name,
+                         int value,
+                         int count) {
+  if (count > 0)
+    UMA_HISTOGRAM_SPARSE_SLOWLY_WITH_VALUE(histogram_name, value, count);
+}
+
 void DataUseReport(const std::string& service_name,
                    const net::URLFetcher* fetcher) {
 #if defined(OS_ANDROID)