[Extensions] Re-enable two Downloads API tests.

The SearchId and SearchIdAndFilename tests were disabled on MSAN
for flakiness. Testing 3000 iterations of each one resulted in no
flaky failures on the MSAN bots.

Bug: 508949
Change-Id: I98a3f9077aff3218e94c2de8b506125175182761
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2229154Reviewed-by: Archana Simha <archanasimha@chromium.org>
Commit-Queue: David Bertoni <dbertoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#776777}

chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc

@@ -1251,14 +1251,7 @@ IN_PROC_BROWSER_TEST_F(DownloadExtensionTest,
 
 // Test the |id| parameter for search().
 //
-// http://crbug.com/508949
-#if defined(MEMORY_SANITIZER)
-#define MAYBE_DownloadExtensionTest_SearchId DISABLED_DownloadExtensionTest_SearchId
-#else
-#define MAYBE_DownloadExtensionTest_SearchId DownloadExtensionTest_SearchId
-#endif
-IN_PROC_BROWSER_TEST_F(DownloadExtensionTest,
-                       MAYBE_DownloadExtensionTest_SearchId) {
+IN_PROC_BROWSER_TEST_F(DownloadExtensionTest, DownloadExtensionTest_SearchId) {
   DownloadManager::DownloadVector items;
   CreateTwoDownloads(&items);
   ScopedItemVectorCanceller delete_items(&items);
@@ -1279,14 +1272,8 @@ IN_PROC_BROWSER_TEST_F(DownloadExtensionTest,
 
 // Test specifying both the |id| and |filename| parameters for search().
 //
-// http://crbug.com/508949
-#if defined(MEMORY_SANITIZER)
-#define MAYBE_DownloadExtensionTest_SearchIdAndFilename DISABLED_DownloadExtensionTest_SearchIdAndFilename
-#else
-#define MAYBE_DownloadExtensionTest_SearchIdAndFilename DownloadExtensionTest_SearchIdAndFilename
-#endif
 IN_PROC_BROWSER_TEST_F(DownloadExtensionTest,
-                       MAYBE_DownloadExtensionTest_SearchIdAndFilename) {
+                       DownloadExtensionTest_SearchIdAndFilename) {
   DownloadManager::DownloadVector items;
   CreateTwoDownloads(&items);
   ScopedItemVectorCanceller delete_items(&items);