Remove MetricsServiceObserver in favor of MetricsProvider.

chrome/browser/metrics/metrics_service_accessor.cc

Index: chrome/browser/metrics/metrics_service_accessor.cc
diff --git a/chrome/browser/metrics/metrics_service_accessor.cc b/chrome/browser/metrics/metrics_service_accessor.cc
index 94c0e88d299a720104db6ace72bee3fd1a9cac4f..15523688fc4a726f32845b879c18552c3a0965b5 100644
--- a/chrome/browser/metrics/metrics_service_accessor.cc
+++ b/chrome/browser/metrics/metrics_service_accessor.cc
@@ -4,31 +4,13 @@
 
 #include "chrome/browser/metrics/metrics_service_accessor.h"
 
-#include "chrome/browser/browser_process.h"
 #include "components/metrics/metrics_service.h"
-#include "components/metrics/metrics_service_observer.h"
 
 // TODO(asvitkine): Remove when this class is moved to metrics namespace.
 using metrics::MetricsService;
-using metrics::MetricsServiceObserver;
 using metrics::SyntheticTrialGroup;
 
 // static
-void MetricsServiceAccessor::AddMetricsServiceObserver(
-    MetricsServiceObserver* observer) {
-  MetricsService* metrics_service = g_browser_process->metrics_service();
-  if (metrics_service)
-    metrics_service->AddObserver(observer);
-}
-
-void MetricsServiceAccessor::RemoveMetricsServiceObserver(
-    MetricsServiceObserver* observer) {
-  MetricsService* metrics_service = g_browser_process->metrics_service();
-  if (metrics_service)
-    metrics_service->RemoveObserver(observer);
-}
-
-// static
 bool MetricsServiceAccessor::RegisterSyntheticFieldTrial(
     MetricsService* metrics_service,
     uint32_t trial_name_hash,