Optimize parameters of list thumbnail loader for MTP volume.

ui/file_manager/file_manager/foreground/js/list_thumbnail_loader_unittest.js

Index: ui/file_manager/file_manager/foreground/js/list_thumbnail_loader_unittest.js
diff --git a/ui/file_manager/file_manager/foreground/js/list_thumbnail_loader_unittest.js b/ui/file_manager/file_manager/foreground/js/list_thumbnail_loader_unittest.js
index a6b5c998043b8a98cc5598d58e159fbad292820e..6e2ea08259f15a097432627a8d2ef9e1d3cfc108 100644
--- a/ui/file_manager/file_manager/foreground/js/list_thumbnail_loader_unittest.js
+++ b/ui/file_manager/file_manager/foreground/js/list_thumbnail_loader_unittest.js
@@ -45,6 +45,7 @@ var listThumbnailLoader;
 var getCallbacks;
 var thumbnailLoadedEvents;
 var fileListModel;
+var currentVolumeType;
 var fileSystem = new MockFileSystem('volume-id');
 var directory1 = new MockDirectoryEntry(fileSystem, '/TestDirectory');
 var entry1 = new MockEntry(fileSystem, '/Test1.jpg');
@@ -55,9 +56,9 @@ var entry5 = new MockEntry(fileSystem, '/Test5.jpg');
 var entry6 = new MockEntry(fileSystem, '/Test6.jpg');
 
 function setUp() {
-  ListThumbnailLoader.NUM_OF_MAX_ACTIVE_TASKS = 2;
-  ListThumbnailLoader.NUM_OF_PREFETCH = 1;
+  currentVolumeType = ListThumbnailLoader.TEST_VOLUME_TYPE;
   ListThumbnailLoader.CACHE_SIZE = 5;
+  ListThumbnailLoader.numOfMaxActiveTasksForTest = 2;
   MockThumbnailLoader.errorUrls = [];
   MockThumbnailLoader.testImageDataUrl = generateSampleImageDataUrl(document);
   MockThumbnailLoader.testImageWidth = 160;
@@ -74,7 +75,15 @@ function setUp() {
 
   fileListModel = new FileListModel(thumbnailModel);
 
-  listThumbnailLoader = new ListThumbnailLoader(fileListModel, thumbnailModel,
+  listThumbnailLoader = new ListThumbnailLoader(
+      fileListModel,
+      thumbnailModel,
+      // Mocking volume manager
+      {
+        getVolumeInfo: function(entry) {
+          return { volumeType: currentVolumeType };
+        }
+      },
       MockThumbnailLoader);
 
   thumbnailLoadedEvents = [];
@@ -189,7 +198,7 @@ function testRangeIsAtTheEndOfList() {
 }
 
 function testCache(callback) {
-  ListThumbnailLoader.NUM_OF_MAX_ACTIVE_TASKS = 5;
+  ListThumbnailLoader.numOfMaxActiveTasksForTest = 5;
 
   // Set high priority range to 0 - 2.
   listThumbnailLoader.setHighPriorityRange(0, 2);
@@ -315,3 +324,16 @@ function testChangeEvent(callback) {
     });
   }), callback);
 }
+
+/**
+ * Test case for MTP volume.
+ */
+function testMTPVolume() {
+  currentVolumeType = VolumeManagerCommon.VolumeType.MTP;
+
+  listThumbnailLoader.setHighPriorityRange(0, 2);
+  fileListModel.push(directory1, entry1, entry2, entry3);
+
+  // Only one request should be enqueued on MTP volume.
+  assertEquals(1, Object.keys(getCallbacks).length);
+}