Zip Archiver: Allow to auto-detect UTF-8 file name when EFS is 0.

We saw a ZIP file created on macOS stores file names in UTF-8 encoding
but the language encoding flag in the general purpose bit is not set.
This change will cover some of such cases when the encoding detector
detected that encoding.

Bug: 903664
Test: browser_tests --gtest_filter=ZipFiles/FilesAppBrowserTest.Test/*
Test: manually verified using the ZIP attached to the bug
Change-Id: I5ef488cf5a0ba04feee9e8d2025054e16785f832
Reviewed-on: https://chromium-review.googlesource.com/c/1328623Reviewed-by: Anand Mistry <amistry@chromium.org>
Commit-Queue: Tatsuhisa Yamaguchi <yamaguchi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607141}

chrome/browser/chromeos/file_manager/file_manager_browsertest.cc

@@ -259,6 +259,7 @@ WRAPPED_INSTANTIATE_TEST_CASE_P(
     ::testing::Values(ZipCase("zipFileOpenDownloads").InGuestMode(),
                       ZipCase("zipFileOpenDownloads"),
                       ZipCase("zipFileOpenDownloadsShiftJIS"),
+                      ZipCase("zipFileOpenDownloadsMacOs"),
                       ZipCase("zipFileOpenDownloadsWithAbsolutePaths"),
                       ZipCase("zipFileOpenDrive").DisableDriveFs(),
                       ZipCase("zipFileOpenDrive").EnableDriveFs(),

chrome/browser/resources/chromeos/zip_archiver/js/volume.js

@@ -219,7 +219,8 @@ unpacker.Volume.ENCODING_TABLE = {
 // supproted by TextEncoder class. We may add more encodings but only if there's
 // evidence that such archives are widespread.
 unpacker.Volume.MIME_TO_ENCODING_TABLE = {
-  'Shift_JIS': 'Shift_JIS'
+  'Shift_JIS': 'Shift_JIS',
+  'UTF-8': 'UTF-8',  // macOS stores file names in UTF-8 without setting EFS
 };
 
 /**

ui/file_manager/integration_tests/file_manager/zip_files.js

@@ -43,6 +43,17 @@ function getUnzippedFileListRowEntriesSjisSubdir() {
   ];
 }
 
+/**
+ * Returns the expected file list row entries after opening (unzipping) the
+ * ENTRIES.zipArchiveMacOs file list entry.
+ */
+function getUnzippedFileListRowEntriesMacOsRoot() {
+  return [
+    // File name in non-ASCII (UTF-8) characters.
+    ['ファイル.dat', '16 bytes', 'DAT file', 'Jul 8, 2001, 12:34 PM']
+  ];
+}
+
 /**
  * Returns the expected file list row entries after opening (unzipping) the
  * ENTRIES.zipArchiveWithAbsolutePaths file list entry.
@@ -466,3 +477,37 @@ testcase.zipFileOpenDownloadsShiftJIS = function() {
     },
   ]);
 };
+
+/**
+ * Tests zip file open (aka unzip) from Downloads. The file name in the archive
+ * is encoded in UTF-8, but the language encoding flag bit is set to 0.
+ */
+testcase.zipFileOpenDownloadsMacOs = function() {
+  let appId;
+
+  StepsRunner.run([
+    // Open Files app on Downloads containing a zip file.
+    function() {
+      setupAndWaitUntilReady(
+          null, RootPath.DOWNLOADS, this.next, [ENTRIES.zipArchiveMacOs], []);
+    },
+    // Select the zip file.
+    function(result) {
+      appId = result.windowId;
+      remoteCall.callRemoteTestUtil('selectFile', appId, ['archive_macos.zip'])
+          .then(this.next);
+    },
+    // Press the Enter key.
+    function(result) {
+      chrome.test.assertTrue(!!result, 'selectFile failed');
+      const key = ['#file-list', 'Enter', false, false, false];
+      remoteCall.callRemoteTestUtil('fakeKeyDown', appId, key, this.next);
+    },
+    // Check: the zip file content should be shown (unzip).
+    function(result) {
+      chrome.test.assertTrue(!!result, 'fakeKeyDown failed');
+      const files = getUnzippedFileListRowEntriesMacOsRoot();
+      remoteCall.waitForFiles(appId, files).then(this.next);
+    },
+  ]);
+};

ui/file_manager/integration_tests/test_util.js

@@ -682,6 +682,17 @@ var ENTRIES = {
     typeText: 'Zip archive'
   }),
 
+  zipArchiveMacOs: new TestEntryInfo({
+    type: EntryType.FILE,
+    sourceFileName: 'archive_macos.zip',
+    targetPath: 'archive_macos.zip',
+    mimeType: 'application/x-zip',
+    lastModifiedTime: 'Dec 21, 2018, 12:21 PM',
+    nameText: 'archive_macos.zip',
+    sizeText: '190 bytes',
+    typeText: 'Zip archive'
+  }),
+
   zipArchiveWithAbsolutePaths: new TestEntryInfo({
     type: EntryType.FILE,
     sourceFileName: 'absolute_paths.zip',