Eliminate //chrome dependencies from MetricsServicesManager

chrome/browser/metrics/chrome_metrics_service_client.h

Index: chrome/browser/metrics/chrome_metrics_service_client.h
diff --git a/chrome/browser/metrics/chrome_metrics_service_client.h b/chrome/browser/metrics/chrome_metrics_service_client.h
index b31bd776c0001dc93db398384768a631d5313688..b79878fbdcef21feb7571e0778eacf6e5c51887e 100644
--- a/chrome/browser/metrics/chrome_metrics_service_client.h
+++ b/chrome/browser/metrics/chrome_metrics_service_client.h
@@ -29,10 +29,6 @@ class PrefService;
 class SigninStatusMetricsProvider;
 #endif
 
-namespace base {
-class FilePath;
-}  // namespace base
-
 namespace metrics {
 class DriveMetricsProvider;
 class MetricsService;
@@ -58,6 +54,7 @@ class ChromeMetricsServiceClient
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
   // metrics::MetricsServiceClient:
+  metrics::MetricsService* GetMetricsService() override;
   void SetMetricsClientId(const std::string& client_id) override;
   void OnRecordingDisabled() override;
   bool IsOffTheRecordSessionActive() override;
@@ -74,10 +71,7 @@ class ChromeMetricsServiceClient
       const base::Callback<void(int)>& on_upload_complete) override;
   base::TimeDelta GetStandardUploadInterval() override;
   base::string16 GetRegistryBackupKey() override;
-
-  metrics::MetricsService* metrics_service() { return metrics_service_.get(); }
-
-  void LogPluginLoadingError(const base::FilePath& plugin_path);
+  void OnPluginLoadingError(const base::FilePath& plugin_path) override;
 
  private:
   explicit ChromeMetricsServiceClient(