Adds histograms for casting feature of Video Player

ui/file_manager/video_player/js/video_player_metrics.js

Index: ui/file_manager/video_player/js/video_player_metrics.js
diff --git a/ui/file_manager/video_player/js/video_player_metrics.js b/ui/file_manager/video_player/js/video_player_metrics.js
new file mode 100644
index 0000000000000000000000000000000000000000..9baa4b019029eb2b8249d78e2f7950eb994156a6
--- /dev/null
+++ b/ui/file_manager/video_player/js/video_player_metrics.js
@@ -0,0 +1,137 @@
+// Copyright (c) 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.
+
+/**
+ * @fileoverview Utility methods for accessing chrome.metricsPrivate API.
+ *
+ * To be included as a first script in main.html
+ */
+
+/**
+ * @extends {metricsBase}
+ */
+var metrics = metricsBase;
+
+/**
+ * Values for "VideoPlayer.CastAPIExtensionStaus" metrics.
+ * @enum {number}
+ */
+metrics.CAST_API_EXTENSION_STATUS = {
+  // Cast API extension is not loaded since the cast extension, which is requred
+  // by the cast API extension, is not installed or load failed.
+  SKIPPED: 0,
+  // Installation of Cast API extension is failed.
+  INSTALLATION_FAILED: 1,
+  // Load of Cast API extension is failed.
+  LOAD_FAILED: 2,
+  // Cast API extension is newly installed and loaded.
+  INSTALLED_AND_LOADED: 3,
+  // Cast API extension is loaded.
+  LOADED: 4,
+  // (sentinel)
+  MAX_VALUE: 4,
+};
+
+/**
+ * Values for "VideoPlayer.PlayType" metrics.
+ * @enum {number}
+ */
+metrics.PLAY_TYPE = {
+  LOCAL: 0,
+  CAST: 1,
+  MAX_VALUE: 1,
+};
+
+/**
+ * Utility function to check if the given value is in the given values.
+ * @param {Object} values
+ * @param {*} value
+ * @reutrn {boolean} True if one or more elements of the given values hash have
+ *     the given value as value. False otherwise.
+ */
+metrics.hasValue_ = function(values, value) {
+  return Object.keys(values).some(function(key) {
+    return values[key] === value;
+  });
+};
+
+/**
+ * Record "VideoPlayer.CastAPIExtensionStatsu" metrics.
+ * @param {metrics.CAST_API_EXTENSION_STATUS} status Status to be recorded.
+ */
+metrics.recordCastAPIExtensionStatus = function(status) {
+  if (!metrics.hasValue_(metrics.CAST_API_EXTENSION_STATUS, status)) {
+    console.error('The given value "' + status + '" is invalid.');
+    return;
+  }
+
+  metrics.recordEnum('CastAPIExtensionStatus',
+                     status,
+                     metrics.CAST_API_EXTENSION_STATUS.MAX_VALUE);
+};
+
+/**
+ * Record "VideoPlayer.NumberOfCastDevices" metrics.
+ * @param {number} number Value to be recorded.
+ */
+metrics.recordNumberOfCastDevices = function(number) {
+  metrics.recordSmallCount('NumberOfCastDevices', number);
+};
+
+/**
+ * Record "VideoPlayer.NumberOfOpenedFile" metrics.
+ * @param {number} number Value to be recorded.
+ */
+metrics.recordNumberOfOpenedFiles = function(number) {
+  metrics.recordSmallCount('NumberOfOpenedFiles', number);
+};
+
+/**
+ * Record "VideoPlayer.CastedVideoLength" metrics.
+ * @param {number} seconds Value to be recorded.
+ */
+metrics.recordCastedVideoLength = function(seconds) {
+  metrics.recordMediumCount('CastedVideoLength', seconds);
+};
+
+/**
+ * Record "VideoPlayer.CastVideoError" metrics.
+ */
+metrics.recordCastVideoErrorAction = function() {
+  metrics.recordUserAction('CastVideoError');
+};
+
+/**
+ * Record "VideoPlayer.OpenVideoPlayer" action.
+ */
+metrics.recordOpenVideoPlayerAction = function() {
+  metrics.recordUserAction('OpenVideoPlayer');
+};
+
+/**
+ * Record "VideoPlayer.PlayType" metrics.
+ * @param {metrics.PLAY_TYPE} type Value to be recorded.
+ */
+metrics.recordPlayType = function(type) {
+  if (!metrics.hasValue_(metrics.PLAY_TYPE, type)) {
+    console.error('The given value "' + status + '" is invalid.');
+    return;
+  }
+
+  metrics.recordEnum('PlayType',
+                     type,
+                     metrics.PLAY_TYPE.MAX_VALUE);
+};
+
+/**
+ * Convert a short metric name to the full format.
+ *
+ * @param {string} name Short metric name.
+ * @return {string} Full metric name.
+ * @override
+ * @private
+ */
+metrics.convertName_ = function(name) {
+  return 'VideoPlayer.' + name;
+};