Disable AutomationApiTest.Mixin on Linux due to flakiness

chrome/browser/extensions/api/automation/automation_apitest.cc

 // Copyright 2014 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 "base/files/file_path.h"
 #include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/extensions/api/automation_internal/automation_util.h"
 #include "chrome/browser/extensions/chrome_extension_function.h"
 #include "chrome/browser/extensions/extension_apitest.h"
@@ skipping 169 matching lines @@
       RunExtensionSubtest("automation/tests/tabs", "queryselector.html"))
       << message_;
 }
 
 IN_PROC_BROWSER_TEST_F(AutomationApiTest, Find) {
   StartEmbeddedTestServer();
   ASSERT_TRUE(RunExtensionSubtest("automation/tests/tabs", "find.html"))
       << message_;
 }
 
+// Flaky on Linux only. http://crbug.com/467921
+#if defined(OS_LINUX)
+#define MAYBE_Mixins DISABLED_Mixins
+#else
+#define MAYBE_Mixins Mixins
+#endif
 IN_PROC_BROWSER_TEST_F(AutomationApiTest, Mixins) {
   StartEmbeddedTestServer();
   ASSERT_TRUE(RunExtensionSubtest("automation/tests/tabs", "mixins.html"))
       << message_;
 }
 
 
 static const int kPid = 1;
 static const int kTab0Rid = 1;
 static const int kTab1Rid = 2;
@@ skipping 312 matching lines @@
       "automationInternal.enableTab",
       FakeAutomationInternalEnableTabFunctionFactory));
   ASSERT_TRUE(extensions::ExtensionFunctionDispatcher::OverrideFunction(
       "automationInternal.performAction",
       FakeAutomationInternalPerformActionFunctionFactory));
   ASSERT_TRUE(RunExtensionSubtest("automation/tests/generated",
                                   "generated_trees.html")) << message_;
 }
 
 }  // namespace extensions