Allow MetricsProviders to request an initial stability log.

components/metrics/metrics_service.h

Index: components/metrics/metrics_service.h
diff --git a/components/metrics/metrics_service.h b/components/metrics/metrics_service.h
index 7a9e08db84d73869ca00b4ec856d541f61be12fa..681841d205ea987fdee5845eec3e3d8c90b023c0 100644
--- a/components/metrics/metrics_service.h
+++ b/components/metrics/metrics_service.h
@@ -320,6 +320,10 @@ class MetricsService : public base::HistogramFlattener {
   // (depending on |state_|), and stages it for upload.
   void StageNewLog();
 
+  // Returns true if the previous run of Chrome crashed, or if any of the
+  // registered metrics providers return true from HasStabilityMetrics.
+  bool ShouldPrepareStabilityLog();
+
   // Prepares the initial stability log, which is only logged when the previous
   // run of Chrome crashed.  This log contains any stability metrics left over
   // from that previous run, and only these stability metrics.  It uses the