Disable AutoSizeSW test on mac because it's flaky.

chrome/browser/apps/web_view_browsertest.cc

 // Copyright 2013 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.
 
 #include "apps/ui/native_app_window.h"
 #include "base/path_service.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/apps/app_browsertest_util.h"
 #include "chrome/browser/automation/automation_util.h"
@@ skipping 615 matching lines @@
 #endif
 
   ASSERT_TRUE(RunPlatformAppTest("platform_apps/web_view/autosize"))
       << message_;
 }
 
 #if !defined(OS_CHROMEOS)
 // This test ensures <webview> doesn't crash in SW rendering when autosize is
 // turned on.
 // Flaky on Windows http://crbug.com/299507
-#if defined(OS_WIN)
+#if defined(OS_WIN) || defined(OS_MACOSX)
 #define MAYBE_AutoSizeSW DISABLED_AutoSizeSW
 #else
 #define MAYBE_AutoSizeSW AutoSizeSW
 #endif
 IN_PROC_BROWSER_TEST_F(WebViewTest, MAYBE_AutoSizeSW) {
   ASSERT_TRUE(RunPlatformAppTest("platform_apps/web_view/autosize"))
       << message_;
 }
 #endif
 
@@ skipping 1232 matching lines @@
 INSTANTIATE_TEST_CASE_P(WithoutThreadedCompositor,
     WebViewCaptureTest,
     ::testing::Values(std::string(switches::kDisableThreadedCompositing)));
 
 // http://crbug.com/171744
 #if !defined(OS_MACOSX)
 INSTANTIATE_TEST_CASE_P(WithThreadedCompositor,
     WebViewCaptureTest,
     ::testing::Values(std::string(switches::kEnableThreadedCompositing)));
 #endif