Add support to mime types in Files app UI.

ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider_unittest.js

Index: ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider_unittest.js
diff --git a/ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider_unittest.js b/ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider_unittest.js
index bd90df862aebeb1fe6595721511de0a44696db69..4ed6af40517cbe868316cbc39e4573a1f8f0c4b1 100644
--- a/ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider_unittest.js
+++ b/ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider_unittest.js
@@ -18,27 +18,6 @@ var entryB = {
   }
 };
 
-function setUp() {
-  chrome.fileManagerPrivate = {
-    getMimeType: function(url, callback) {
-      chrome.fileManagerPrivate.isGetMimeTypeCalled_ = true;
-
-      switch (url) {
-        case 'filesystem://A':
-          callback('application/A');
-          break;
-        case 'filesystem://B':
-          callback('application/B');
-          break;
-        default:
-          callback('');
-          break;
-      }
-    },
-    isGetMimeTypeCalled_: false
-  };
-}
-
 function testFileSystemMetadataProviderBasic(callback) {
   var provider = new FileSystemMetadataProvider();
   var names = [
@@ -53,14 +32,12 @@ function testFileSystemMetadataProviderBasic(callback) {
         new Date(2015, 1, 1).toString(),
         results[0].modificationTime.toString());
     assertEquals(1024, results[0].size);
-    assertEquals('application/A', results[0].contentMimeType);
     assertTrue(results[0].present);
     assertTrue(results[0].availableOffline);
     assertEquals(
         new Date(2015, 2, 2).toString(),
         results[1].modificationTime.toString());
     assertEquals(2048, results[1].size);
-    assertEquals('application/B', results[1].contentMimeType);
     assertTrue(results[1].present);
     assertTrue(results[1].availableOffline);
   }), callback);
@@ -76,8 +53,5 @@ function testFileSystemMetadataProviderPartialRequest(callback) {
             new Date(2015, 1, 1).toString(),
             results[0].modificationTime.toString());
         assertEquals(1024, results[0].size);
-        // When contentMimeType is not requested, this shouldn't try to get
-        // MIME type.
-        assertFalse(chrome.fileManagerPrivate.isGetMimeTypeCalled_);
       }), callback);
 }