Add initial Controller to DownloadService

components/download/internal/stats.h

Index: components/download/internal/stats.h
diff --git a/components/download/internal/stats.h b/components/download/internal/stats.h
new file mode 100644
index 0000000000000000000000000000000000000000..51427601b82c3738a93d14bb2cf80a522db8ef3a
--- /dev/null
+++ b/components/download/internal/stats.h
@@ -0,0 +1,81 @@
+// Copyright 2017 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_DOWNLOAD_INTERNAL_STATS_H_
+#define COMPONENTS_DOWNLOAD_INTERNAL_STATS_H_
+
+#include "components/download/public/clients.h"
+#include "components/download/public/download_params.h"
+
+namespace download {
+
+struct StartupStatus;
+
+namespace stats {
+
+// Please follow the following rules for all enums:
+// 1. Keep them in sync with the corresponding entry in enums.xml.
+// 2. Treat them as append only.
+// 3. Do not remove any enums.  Only mark them as deprecated.
+
+// Enum used by UMA metrics to track which actions a Client is taking on the
+// service.
+enum class ServiceApiAction {
+  // Represents a call to DownloadService::StartDownload.
+  START_DOWNLOAD = 0,
+
+  // Represents a call to DownloadService::PauseDownload.
+  PAUSE_DOWNLOAD = 1,
+
+  // Represents a call to DownloadService::ResumeDownload.
+  RESUME_DOWNLOAD = 2,
+
+  // Represents a call to DownloadService::CancelDownload.
+  CANCEL_DOWNLOAD = 3,
+
+  // Represents a call to DownloadService::ChangeCriteria.
+  CHANGE_CRITERIA = 4,
+
+  // The last entry for the enum.
+  COUNT = 5,
+};
+
+// Enum used by UMA metrics to tie to specific actions taken on a Model.  This
+// can be used to track failure events.
+enum class ModelAction {
+  // Represents an attempt to initialize the Model.
+  INITIALIZE = 0,
+
+  // Represents an attempt to add an Entry to the Model.
+  ADD = 1,
+
+  // Represents an attempt to update an Entry in the Model.
+  UPDATE = 2,
+
+  // Represents an attempt to remove an Entry from the Model.
+  REMOVE = 3,
+
+  // The last entry for the enum.
+  COUNT = 4,
+};
+
+// Logs the results of starting up the Controller.  Will log each failure reason
+// if |status| contains more than one initialization failure.
+void LogControllerStartupStatus(const StartupStatus& status);
+
+// Logs an action taken on the service API.
+void LogServiceApiAction(DownloadClient client, ServiceApiAction action);
+
+// Logs the result of a StartDownload() attempt on the service.
+void LogStartDownloadResult(DownloadClient client,
+                            DownloadParams::StartResult result);
+
+// Logs statistics about the result of a Model operation.  Used to track failure
+// cases.
+void LogModelOperationResult(ModelAction action, bool success);
+
+}  // namespace stats
+}  // namespace download
+
+#endif  // COMPONENTS_DOWNLOAD_INTERNAL_STATS_H_