Break down 'other' in FileBrowser.QuickView.FileType UMA

Break down 'other' in FileBrowser.QuickView.FileType UMA to 'directory',
'no extension' and 'unknown extension'.

extension and a file with a .gn extension. Then check
values 59 through 62 inclusive

Bug: 772599
Test: Quick View and Open on a folder, a .zip file, a file without an
chrome: //histograms has 4 entries for FileBrowser.QuickView.FileType,
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Id13b8734e96b238bfb98b98b0062d1f0721180c7
Reviewed-on: https://chromium-review.googlesource.com/907992Reviewed-by: Naoki Fukino <fukino@chromium.org>
Commit-Queue: Sasha Morrissey <sashab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#536027}

tools/metrics/histograms/enums.xml

@@ -44529,6 +44529,9 @@ Called by update_traffic_annotation_histograms.py.-->
   <int value="57" label=".torrent"/>
   <int value="58" label=".txt"/>
   <int value="59" label=".zip"/>
+  <int value="60" label="directory"/>
+  <int value="61" label="no extension"/>
+  <int value="62" label="unknown extension"/>
 </enum>
 
 <enum name="VirtualKeyboardControllerState">

ui/file_manager/file_manager/foreground/js/file_tasks.js

@@ -289,18 +289,33 @@ FileTasks.prototype.openSuggestAppsDialog = function(
  * The list of known extensions to record UMA.
  * Note: Because the data is recorded by the index, so new item shouldn't be
  * inserted.
+ * Must match the ViewFileType entry in enums.xml.
  *
  * @const
  * @type {Array<string>}
  */
 FileTasks.UMA_INDEX_KNOWN_EXTENSIONS = Object.freeze([
-  'other', '.3ga', '.3gp', '.aac', '.alac', '.asf', '.avi', '.bmp', '.csv',
-  '.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', '.crdownload', '.crx', '.dmg', '.exe',
-  '.html', 'htm', '.jar', '.ps', '.torrent', '.txt', '.zip',
+  'other',     '.3ga',         '.3gp',
+  '.aac',      '.alac',        '.asf',
+  '.avi',      '.bmp',         '.csv',
+  '.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',     '.crdownload',  '.crx',
+  '.dmg',      '.exe',         '.html',
+  'htm',       '.jar',         '.ps',
+  '.torrent',  '.txt',         '.zip',
+  'directory', 'no extension', 'unknown extension'
 ]);
 
 /**

ui/file_manager/file_manager/foreground/js/quick_view_uma.js

@@ -74,8 +74,12 @@ QuickViewUma.VolumeType = [
  */
 QuickViewUma.prototype.exportFileType_ = function(entry, name) {
   var extension = FileType.getExtension(entry).toLowerCase();
-  if (FileTasks.UMA_INDEX_KNOWN_EXTENSIONS.indexOf(extension) < 0) {
-    extension = 'other';
+  if (entry.isDirectory) {
+    extension = 'directory';
+  } else if (extension === '') {
+    extension = 'no extension';
+  } else if (FileTasks.UMA_INDEX_KNOWN_EXTENSIONS.indexOf(extension) < 0) {
+    extension = 'unknown extension';
   }
   metrics.recordEnum(name, extension, FileTasks.UMA_INDEX_KNOWN_EXTENSIONS);
 };