Move the thread hop for UMA user actions from content:: to base::.

components/metrics/test_metrics_service_client.h

Index: components/metrics/test_metrics_service_client.h
diff --git a/components/metrics/test_metrics_service_client.h b/components/metrics/test_metrics_service_client.h
index 8710355901ce5486be15079275b49962130f12a3..3b551ad52e3e1dc98d3523405363ab9af618040c 100644
--- a/components/metrics/test_metrics_service_client.h
+++ b/components/metrics/test_metrics_service_client.h
@@ -40,9 +40,12 @@ class TestMetricsServiceClient : public MetricsServiceClient {
   scoped_ptr<MetricsLogUploader> CreateUploader(
       const base::Callback<void(int)>& on_upload_complete) override;
   base::TimeDelta GetStandardUploadInterval() override;
+  scoped_refptr<base::SingleThreadTaskRunner>
+      GetMainThreadTaskRunner() override;
   bool IsReportingPolicyManaged() override;
   MetricsServiceClient::EnableMetricsDefault GetDefaultOptIn() override;
 
+

[Ilya Sherman, 2016/04/07 18:21:54]

nit: Spurious newline.

[beaudoin, 2016/04/07 21:12:58]

Done.

   const std::string& get_client_id() const { return client_id_; }
   void set_version_string(const std::string& str) { version_string_ = str; }
   void set_product(int32_t product) { product_ = product; }
@@ -60,6 +63,7 @@ class TestMetricsServiceClient : public MetricsServiceClient {
   int32_t product_;
   bool reporting_is_managed_;
   MetricsServiceClient::EnableMetricsDefault enable_default_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(TestMetricsServiceClient);
 };