Add an IPC method for Blink to call RapporService::RecordSample()

components/rappor/rappor_service.h

Index: components/rappor/rappor_service.h
diff --git a/components/rappor/rappor_service.h b/components/rappor/rappor_service.h
index d50b91e9ca2edda4878a7314e5344b94e16e6c7d..b4fb029f377ec51379a84eaab2ff7cbcb1297cae 100644
--- a/components/rappor/rappor_service.h
+++ b/components/rappor/rappor_service.h
@@ -12,6 +12,7 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/metrics/user_metrics.h"
 #include "base/timer/timer.h"
 #include "components/metrics/daily_event.h"
 #include "components/rappor/rappor_parameters.h"
@@ -108,6 +109,11 @@ class RapporService {
   // reports and pass it to the uploader.
   void OnLogInterval();
 
+  void EnableRecordFromUserMetrics();
+  void OnUserMetricsCallback(
+      const std::string& metric,
+      const std::string& sample);
+
   // Finds a metric in the metrics_map_, creating it if it doesn't already
   // exist.
   RapporMetric* LookUpMetric(const std::string& metric_name,
@@ -141,6 +147,8 @@ class RapporService {
   // The map owns the metrics it contains.
   std::map<std::string, RapporMetric*> metrics_map_;
 
+  base::RapporCallback user_metrics_callback_;
+
   DISALLOW_COPY_AND_ASSIGN(RapporService);
 };