Move EntropyProvider Source From MetricsService to MetricsServicesManager

components/metrics_services_manager/metrics_services_manager.h

Index: components/metrics_services_manager/metrics_services_manager.h
diff --git a/components/metrics_services_manager/metrics_services_manager.h b/components/metrics_services_manager/metrics_services_manager.h
index d559ffbd92e4629be2c993256d4c467b2f7db223..e70d6489066c40e1278f51c593097ec4d3d2b647 100644
--- a/components/metrics_services_manager/metrics_services_manager.h
+++ b/components/metrics_services_manager/metrics_services_manager.h
@@ -8,6 +8,7 @@
 #include <memory>
 
 #include "base/macros.h"
+#include "base/metrics/field_trial.h"
 #include "base/threading/thread_checker.h"
 
 namespace base {
@@ -42,6 +43,16 @@ class MetricsServicesManager {
       std::unique_ptr<MetricsServicesManagerClient> client);
   virtual ~MetricsServicesManager();
 
+  // Returns the preferred entropy provider used to seed persistent activities
+  // based on whether or not metrics reporting is permitted on this client.
+  //
+  // If there's consent to report metrics, this method returns an entropy
+  // provider that has a high source of entropy, partially based on the client
+  // ID. Otherwise, it returns an entropy provider that is based on a low
+  // entropy source.
+  std::unique_ptr<const base::FieldTrial::EntropyProvider>
+  CreateEntropyProvider();

[brettw, 2016/09/14 22:22:03]

Indent 4 spaces as above.

[sdefresne, 2016/09/15 11:30:07]

I think this is correctly indented (at least this is how clang-format indents
methods).

[robliao, 2016/09/15 14:31:18]

The stated rule:
If you break after the return type of a function declaration or definition, do
not indent.
https://google.github.io/styleguide/cppguide.html#Function_Declarations_and_D...

Personally, I would prefer the 4 space indent here.

+
   // Returns the MetricsService, creating it if it hasn't been created yet (and
   // additionally creating the MetricsServiceClient in that case).
   metrics::MetricsService* GetMetricsService();