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

components/metrics/metrics_service_client.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_METRICS_METRICS_SERVICE_CLIENT_H_
 #define COMPONENTS_METRICS_METRICS_SERVICE_CLIENT_H_
 
 #include <stdint.h>
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/single_thread_task_runner.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "components/metrics/proto/system_profile.pb.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace metrics {
 
@@ skipping 69 matching lines @@
       const base::Closure& done_callback) = 0;
 
   // Creates a MetricsLogUploader with the specified parameters (see comments on
   // MetricsLogUploader for details).
   virtual scoped_ptr<MetricsLogUploader> CreateUploader(
       const base::Callback<void(int)>& on_upload_complete) = 0;
 
   // Returns the standard interval between upload attempts.
   virtual base::TimeDelta GetStandardUploadInterval() = 0;
 
+  virtual scoped_refptr<base::SingleThreadTaskRunner>
+      GetUIThreadTaskRunner() = 0;

[Ilya Sherman, 2016/04/06 02:36:29]

Please document this method.

[Ilya Sherman, 2016/04/06 02:36:29]

nit: I think "MainThread" would be better than "UIThread".

[beaudoin, 2016/04/06 15:06:13]

Done.

[beaudoin, 2016/04/06 15:06:13]

Done.

+
   // Returns the name of a key under HKEY_CURRENT_USER that can be used to store
   // backups of metrics data. Unused except on Windows.
   virtual base::string16 GetRegistryBackupKey();
 
   // Called on plugin loading errors.
   virtual void OnPluginLoadingError(const base::FilePath& plugin_path) {}
 
   // Called on renderer crashes in some embedders (e.g., those that do not use
   // //content and thus do not have //content's notification system available
   // as a mechanism for observing renderer crashes).
   virtual void OnRendererProcessCrash() {}
 
   // Returns whether metrics reporting is managed by policy.
   virtual bool IsReportingPolicyManaged();
 
   // Gets information about the default value for the enable metrics reporting
   // checkbox shown during first-run.
   virtual EnableMetricsDefault GetDefaultOptIn();
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_METRICS_SERVICE_CLIENT_H_