[fsp] Let extensions decide about the file system id.

chrome/test/data/extensions/api_test/file_system_provider/read_file/test.js

Index: chrome/test/data/extensions/api_test/file_system_provider/read_file/test.js
diff --git a/chrome/test/data/extensions/api_test/file_system_provider/read_file/test.js b/chrome/test/data/extensions/api_test/file_system_provider/read_file/test.js
index b9d7b0846a3f040030f247c015e21752daa74bf6..6cff9d2be9bf8e01534d3c4de77dd54166946864 100644
--- a/chrome/test/data/extensions/api_test/file_system_provider/read_file/test.js
+++ b/chrome/test/data/extensions/api_test/file_system_provider/read_file/test.js
@@ -5,12 +5,7 @@
 'use strict';
 
 /**
- * @type {number}
- */
-var fileSystemId = 0;
-
-/**
- * @type {?DOMFileSystem}
+ * @type {DOMFileSystem}
  */
 var fileSystem = null;
 
@@ -22,6 +17,12 @@ var fileSystem = null;
 var openedFiles = {};
 
 /**
+ * @type {string}
+ * @const
+ */
+var FILE_SYSTEM_ID = 'chocolate-id';
+
+/**
  * @type {Object}
  * @const
  */
@@ -64,20 +65,39 @@ var TESTING_BROKEN_TIRAMISU_FILE = Object.freeze({
 });
 
 /**
+ * Gets volume information for the provided file system.
+ *
+ * @param {string} fileSystemId Id of the provided file system.
+ * @param {function(Object)} callback Callback to be called on result, with the
+ *     volume information object in case of success, or null if not found.
+ */
+function getVolumeInfo(fileSystemId, callback) {
+  chrome.fileBrowserPrivate.getVolumeMetadataList(function(volumeList) {
+    for (var i = 0; i < volumeList.length; i++) {
+      if (volumeList[i].extensionId == chrome.runtime.id &&
+          volumeList[i].fileSystemId == fileSystemId) {
+        callback(volumeList[i]);
+        return;
+      }
+    }
+    callback(null);
+  });
+}
+
+/**
  * Returns metadata for the requested entry.
  *
  * To successfully acquire a DirectoryEntry, or even a DOMFileSystem, this event
  * must be implemented and return correct values.
  *
- * @param {number} inFileSystemId ID of the file system.
+ * @param {string} inFileSystemId ID of the file system.
  * @param {string} entryPath Path of the requested entry.
  * @param {function(Object)} onSuccess Success callback with metadata passed
  *     an argument.
  * @param {function(string)} onError Error callback with an error code.
  */
-function onGetMetadataRequested(
-    inFileSystemId, entryPath, onSuccess, onError) {
-  if (inFileSystemId != fileSystemId) {
+function onGetMetadataRequested(inFileSystemId, entryPath, onSuccess, onError) {
+  if (inFileSystemId != FILE_SYSTEM_ID) {
     onError('SECURITY_ERROR');  // enum ProviderError.
     return;
   }
@@ -104,7 +124,7 @@ function onGetMetadataRequested(
  * Requests opening a file at <code>filePath</code>. Further file operations
  * will be associated with the <code>requestId</code>
  *
- * @param {number} inFileSystemId ID of the file system.
+ * @param {string} inFileSystemId ID of the file system.
  * @param {number} requestId ID of the opening request. Used later for reading.
  * @param {string} filePath Path of the file to be opened.
  * @param {string} mode Mode, either reading or writing.
@@ -114,7 +134,7 @@ function onGetMetadataRequested(
  */
 function onOpenFileRequested(
     inFileSystemId, requestId, filePath, mode, create, onSuccess, onError) {
-  if (inFileSystemId != fileSystemId || mode != 'READ' || create) {
+  if (inFileSystemId != FILE_SYSTEM_ID || mode != 'READ' || create) {
     onError('SECURITY_ERROR');  // enum ProviderError.
     return;
   }
@@ -131,14 +151,14 @@ function onOpenFileRequested(
 /**
  * Requests closing a file previously opened with <code>openRequestId</code>.
  *
- * @param {number} inFileSystemId ID of the file system.
+ * @param {string} inFileSystemId ID of the file system.
  * @param {number} openRequestId ID of the request used to open the file.
  * @param {function()} onSuccess Success callback.
  * @param {function(string)} onError Error callback.
  */
 function onCloseFileRequested(
     inFileSystemId, openRequestId, onSuccess, onError) {
-  if (inFileSystemId != fileSystemId || !openedFiles[openRequestId]) {
+  if (inFileSystemId != FILE_SYSTEM_ID || !openedFiles[openRequestId]) {
     onError('SECURITY_ERROR');  // enum ProviderError.
     return;
   }
@@ -151,7 +171,7 @@ function onCloseFileRequested(
  * Requests reading contents of a file, previously opened with <code>
  * openRequestId</code>.
  *
- * @param {number} inFileSystemId ID of the file system.
+ * @param {string} inFileSystemId ID of the file system.
  * @param {number} openRequestId ID of the request used to open the file.
  * @param {number} offset Offset of the file.
  * @param {number} length Number of bytes to read.
@@ -162,7 +182,7 @@ function onCloseFileRequested(
 function onReadFileRequested(
     inFileSystemId, openRequestId, offset, length, onSuccess, onError) {
   var filePath = openedFiles[openRequestId];
-  if (inFileSystemId != fileSystemId || !filePath) {
+  if (inFileSystemId != FILE_SYSTEM_ID || !filePath) {
     onError('SECURITY_ERROR');  // enum ProviderError.
     return;
   }
@@ -201,8 +221,7 @@ function onReadFileRequested(
  * @param {function()} callback Success callback.
  */
 function setUp(callback) {
-  chrome.fileSystemProvider.mount('chocolate.zip', function(id) {
-    fileSystemId = id;
+  chrome.fileSystemProvider.mount(FILE_SYSTEM_ID, 'chocolate.zip', function() {
     chrome.fileSystemProvider.onGetMetadataRequested.addListener(
         onGetMetadataRequested);
     chrome.fileSystemProvider.onOpenFileRequested.addListener(
@@ -210,16 +229,19 @@ function setUp(callback) {
     chrome.fileSystemProvider.onReadFileRequested.addListener(
         onReadFileRequested);
     var volumeId =
-        'provided:' + chrome.runtime.id + '-' + fileSystemId + '-user';
+        'provided:' + chrome.runtime.id + '-' + FILE_SYSTEM_ID + '-user';
 
-    chrome.fileBrowserPrivate.requestFileSystem(
-        volumeId,
-        function(inFileSystem) {
-          chrome.test.assertTrue(!!inFileSystem);
+    getVolumeInfo(FILE_SYSTEM_ID, function(volumeInfo) {
+      chrome.test.assertTrue(!!volumeInfo);
+      chrome.fileBrowserPrivate.requestFileSystem(
+          volumeInfo.volumeId,
+          function(inFileSystem) {
+            chrome.test.assertTrue(!!inFileSystem);
 
-          fileSystem = inFileSystem;
-          callback();
-        });
+            fileSystem = inFileSystem;
+            callback();
+          });
+    });
   }, function() {
     chrome.test.fail();
   });