Disable flaky ExtensionToolbarModelTest.SizeAfterPrefChange on Linux/Chrome OS

chrome/browser/extensions/extension_toolbar_model_browsertest.cc

 // Copyright (c) 2011 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/macros.h"
 #include "chrome/browser/extensions/extension_browsertest.h"
 #include "chrome/browser/extensions/extension_toolbar_model.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/test/base/in_process_browser_test.h"
@@ skipping 566 matching lines @@
 
   // When we stop highlighting, we should see the new extension show up.
   model_->StopHighlighting();
   EXPECT_FALSE(model_->is_highlighting());
   EXPECT_EQ(3u, model_->toolbar_items().size());
   EXPECT_EQ(id_a, ExtensionAt(0)->id());
   EXPECT_EQ(id_b, ExtensionAt(1)->id());
   EXPECT_EQ(id_c, ExtensionAt(2)->id());
 }
 
-IN_PROC_BROWSER_TEST_F(ExtensionToolbarModelTest, SizeAfterPrefChange) {
+// Test is flaky on Linus and ChromeOS, see crbug.com/379170.
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
+#define MAYBE_SizeAfterPrefChange DISABLED_SizeAfterPrefChange
+#else
+#define MAYBE_SizeAfterPrefChange SizeAfterPrefChange
+#endif
+IN_PROC_BROWSER_TEST_F(ExtensionToolbarModelTest, MAYBE_SizeAfterPrefChange) {
   // Load two extensions with browser action.
   base::FilePath extension_a_path(test_data_dir_.AppendASCII("api_test")
                                                 .AppendASCII("browser_action")
                                                 .AppendASCII("basics"));
   ASSERT_TRUE(LoadExtension(extension_a_path));
   base::FilePath extension_b_path(test_data_dir_.AppendASCII("api_test")
                                                 .AppendASCII("browser_action")
                                                 .AppendASCII("popup"));
   ASSERT_TRUE(LoadExtension(extension_b_path));
   std::string id_a = ExtensionAt(0)->id();
   std::string id_b = ExtensionAt(1)->id();
 
   // Should be at max size (-1).
   EXPECT_EQ(-1, model_->GetVisibleIconCount());
 
   model_->OnExtensionToolbarPrefChange();
 
   // Should still be at max size.
   EXPECT_EQ(-1, model_->GetVisibleIconCount());
 }
 
 }  // namespace extensions