Fix UMA recoding code for FileBrowser.ViewingFileType.

chrome/browser/resources/file_manager/foreground/js/file_tasks.js

Index: chrome/browser/resources/file_manager/foreground/js/file_tasks.js
diff --git a/chrome/browser/resources/file_manager/foreground/js/file_tasks.js b/chrome/browser/resources/file_manager/foreground/js/file_tasks.js
index 474e9d9813f80a4900dbf493245940dffc4f7008..dff222f382bbdfd7cae1be9e335fe06e2d7287dd 100644
--- a/chrome/browser/resources/file_manager/foreground/js/file_tasks.js
+++ b/chrome/browser/resources/file_manager/foreground/js/file_tasks.js
@@ -133,14 +133,14 @@ FileTasks.prototype.onTasks_ = function(tasks) {
  * @type {Array.<string>}
  * @private
  */
-FileTasks.knownExtensions_ = [
+FileTasks.UMA_INDEX_KNOWN_EXTENSIONS_ = Object.freeze([
   'other', '.3ga', '.3gp', '.aac', '.alac', '.asf', '.avi', '.bmp', '.csv',
-  '.doc', '.docx', '.flac', '.gif', '.ico', '.jpeg', '.jpg', '.log', '.m3u',
-  '.m3u8', '.m4a', '.m4v', '.mid', '.mkv', '.mov', '.mp3', '.mp4', '.mpg',
-  '.odf', '.odp', '.ods', '.odt', '.oga', '.ogg', '.ogv', '.pdf', '.png',
-  '.ppt', '.pptx', '.ra', '.ram', '.rar', '.rm', '.rtf', '.wav', '.webm',
-  '.webp', '.wma', '.wmv', '.xls', '.xlsx',
-];
+  '.doc', '.docx', '.flac', '.gif', '.jpeg', '.jpg', '.log', '.m3u', '.m3u8',
+  '.m4a', '.m4v', '.mid', '.mkv', '.mov', '.mp3', '.mp4', '.mpg', '.odf',
+  '.odp', '.ods', '.odt', '.oga', '.ogg', '.ogv', '.pdf', '.png', '.ppt',
+  '.pptx', '.ra', '.ram', '.rar', '.rm', '.rtf', '.wav', '.webm', '.webp',
+  '.wma', '.wmv', '.xls', '.xlsx',
+]);
 
 /**
  * The list of excutable file extensions.
@@ -172,11 +172,11 @@ FileTasks.recordViewingFileTypeUMA_ = function(entries) {
   for (var i = 0; i < entries.length; i++) {
     var entry = entries[i];
     var extension = FileType.getExtension(entry).toLowerCase();
-    if (FileTasks.knownExtensions_.indexOf(extension) < 0) {
+    if (FileTasks.UMA_INDEX_KNOWN_EXTENSIONS_.indexOf(extension) < 0) {
       extension = 'other';
     }
     metrics.recordEnum(
-        'ViewingFileType', extension, FileTasks.knownExtensions_);
+        'ViewingFileType', extension, FileTasks.UMA_INDEX_KNOWN_EXTENSIONS_);
   }
 };