Disable DownloadExtensionTest_OnDeterminingFilename_InterruptedResume on Mac as well.

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

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Disable everything on windows only. http://crbug.com/306144
 #ifndef OS_WIN
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 3981 matching lines @@
                           GetFilename("42 (1).txt").c_str())));
   ASSERT_TRUE(WaitFor(downloads::OnChanged::kEventName,
                       base::StringPrintf(
                           "[{\"id\": %d,"
                           "  \"state\": {"
                           "    \"previous\": \"in_progress\","
                           "    \"current\": \"complete\"}}]",
                           result_id)));
 }
 
-#if defined(OS_WIN) || defined(OS_CHROMEOS) || defined(OS_LINUX)
 // This test is very flaky on Win XP and Aura. http://crbug.com/248438
 // Also flaky on Linux. http://crbug.com/700382
-#define MAYBE_DownloadExtensionTest_OnDeterminingFilename_InterruptedResume \
-    DISABLED_DownloadExtensionTest_OnDeterminingFilename_InterruptedResume
-#else
-#define MAYBE_DownloadExtensionTest_OnDeterminingFilename_InterruptedResume \
-    DownloadExtensionTest_OnDeterminingFilename_InterruptedResume
-#endif
-
+// Also flaky on Mac ASAN with PlzNavigate.
 // Test download interruption while extensions determining filename. Should not
 // re-dispatch onDeterminingFilename.
 IN_PROC_BROWSER_TEST_F(
     DownloadExtensionTest,
-    MAYBE_DownloadExtensionTest_OnDeterminingFilename_InterruptedResume) {
+    DISABLED_DownloadExtensionTest_OnDeterminingFilename_InterruptedResume) {
   LoadExtension("downloads_split");
   ASSERT_TRUE(StartEmbeddedTestServer());
   GoOnTheRecord();
   content::RenderProcessHost* host = AddFilenameDeterminer();
 
   // Start a download.
   DownloadItem* item = NULL;
   {
     DownloadManager* manager = GetCurrentManager();
     std::unique_ptr<content::DownloadTestObserver> observer(
@@ skipping 277 matching lines @@
   EXPECT_EQ(downloads::FILENAME_CONFLICT_ACTION_PROMPT, conflict_action);
   EXPECT_FALSE(warnings.empty());
   EXPECT_EQ(Warning::kDownloadFilenameConflict,
             warnings.begin()->warning_type());
   EXPECT_EQ("incumbent", warnings.begin()->extension_id());
 }
 
 }  // namespace extensions
 
 #endif  // http://crbug.com/306144