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..84133f3ca65fedd674ffa9ad225cc1e73d05201d
--- /dev/null
+++ b/ui/file_manager/video_player/js/video_player_metrics.js
@@ -0,0 +1,130 @@
+// 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.CastExtensionStaus" metrics.
+ * @enum {number}
+ */
+metrics.CAST_EXTENSION = {
+  EXTENSION_UNAVAILABLE: 0,
+  API_INSTALLATION_FAILED: 1,
+  API_LOAD_FAILED: 2,
+  API_INSTALLED_AND_LOADED: 3,
+  API_AVAILABLE_AND_LOADED: 4,
+  MAX_VALUE: 4,
+};
+
+/**
+ * Values for "VideoPlayer.PlayType" metrics.
+ * @enum {number}
+ */
+metrics.PLAY_TYPE = {
+  LOCAL: 0,
+  CAST: 1,
+  MAX_VALUE: 1,

[Ilya Sherman, 2014/12/09 01:57:49]

Unless the JS metrics API is different from the C++ metrics API -- and to the
best of my knowledge it isn't -- you should set this constant to
one-past-the-end, rather than equal to the max value.  Otherwise, if you ever
extend this histogram to include any additional play types, the metrics will get
confused.

(If you're curious, the final value passed to recordEnum defines an overflow
bucket, and it's best not to emit any data to the overflow bucket -- this both
enables error-checking, and means that the size of the last bucket that you emit
to doesn't change when you append more buckets.)

[yoshiki, 2014/12/10 03:20:50]

In the base class, the final value is passed with adding 1 so the issue is not
happened.

https://code.google.com/p/chromium/codesearch#chromium/src/ui/file_manager/fi...

But I think we should match it with the C++ metrics API. I'll do this work in
separate patch as filed http://crbug.com/440645.

+};
+
+/**
+ * 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.CastExtensionStatsu" metrics.
+ * @param {metrics.CAST_EXTENSION} status Status to be recorded.
+ */
+metrics.recordCastExtensionStatus = function(status) {
+  if (!metrics.hasValue_(metrics.CAST_EXTENSION, status)) {
+    console.error('The given value "' + status + '" is invalid.');
+    return;
+  }
+
+  metrics.recordEnum('CastExtensionStatus',
+                     status,
+                     metrics.CAST_EXTENSION.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');

[Ilya Sherman, 2014/12/09 01:57:49]

I don't see this defined in actions.xml

[yoshiki, 2014/12/10 03:20:50]

I accidentally removed. Added.

+};
+
+/**
+ * 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;
+};