Re-enable ChromeVox download tests

These tests appear to be stable on release and debug.

R=akihiroota@chromium.org

Bug: none
Change-Id: I838022efab03c267f27e68b642ca3c0749935b37
AX-Relnotes: n/a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2587689
Commit-Queue: David Tseng <dtseng@chromium.org>
Commit-Queue: Akihiro Ota <akihiroota@chromium.org>
Auto-Submit: David Tseng <dtseng@chromium.org>
Reviewed-by: Akihiro Ota <akihiroota@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836365}

chrome/browser/resources/chromeos/accessibility/chromevox/background/download_handler_test.js

@@ -199,8 +199,7 @@ TEST_F('ChromeVoxDownloadTest', 'DownloadResumedTest', function() {
 });
 
 TEST_F(
-    'ChromeVoxDownloadTest', 'DISABLED_DownloadOneSecondRemainingTest',
-    function() {
+    'ChromeVoxDownloadTest', 'DownloadOneSecondRemainingTest', function() {
       localStorage['announceDownloadNotifications'] = 'true';
       this.addFakeApi('second');
       const mockFeedback = this.createMockFeedback();
@@ -224,7 +223,7 @@ TEST_F(
     });
 
 TEST_F(
-    'ChromeVoxDownloadTest', 'DISABLED_DownloadMultipleSecondsRemainingTest',
+    'ChromeVoxDownloadTest', 'DownloadMultipleSecondsRemainingTest',
     function() {
       localStorage['announceDownloadNotifications'] = 'true';
       this.addFakeApi('seconds');
@@ -249,8 +248,7 @@ TEST_F(
     });
 
 TEST_F(
-    'ChromeVoxDownloadTest', 'DISABLED_DownloadOneMinuteRemainingTest',
-    function() {
+    'ChromeVoxDownloadTest', 'DownloadOneMinuteRemainingTest', function() {
       localStorage['announceDownloadNotifications'] = 'true';
       this.addFakeApi('minute');
       const mockFeedback = this.createMockFeedback();
@@ -274,7 +272,7 @@ TEST_F(
     });
 
 TEST_F(
-    'ChromeVoxDownloadTest', 'DISABLED_DownloadMultipleMinutesRemainingTest',
+    'ChromeVoxDownloadTest', 'DownloadMultipleMinutesRemainingTest',
     function() {
       localStorage['announceDownloadNotifications'] = 'true';
       this.addFakeApi('minutes');
@@ -299,8 +297,7 @@ TEST_F(
     });
 
 TEST_F(
-    'ChromeVoxDownloadTest', 'DISABLED_DownloadOneHourRemainingTest',
-    function() {
+    'ChromeVoxDownloadTest', 'DownloadOneHourRemainingTest', function() {
       localStorage['announceDownloadNotifications'] = 'true';
       this.addFakeApi('hour');
       const mockFeedback = this.createMockFeedback();
@@ -324,8 +321,7 @@ TEST_F(
     });
 
 TEST_F(
-    'ChromeVoxDownloadTest', 'DISABLED_DownloadMultipleHoursRemainingTest',
-    function() {
+    'ChromeVoxDownloadTest', 'DownloadMultipleHoursRemainingTest', function() {
       localStorage['announceDownloadNotifications'] = 'true';
       this.addFakeApi('hours');
       const mockFeedback = this.createMockFeedback();