Don't allow navigations in inactive windows to change window focus.

chrome/test/base/web_ui_browser_test.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 "chrome/test/base/web_ui_browser_test.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <vector>
@@ skipping 204 matching lines @@
 
 void WebUIBrowserTest::BrowsePreload(const GURL& browse_to) {
   content::WebContents* web_contents =
       browser()->tab_strip_model()->GetActiveWebContents();
   WebUIJsInjectionReadyObserver injection_observer(
       web_contents, this, preload_test_fixture_, preload_test_name_);
   content::TestNavigationObserver navigation_observer(web_contents);
   chrome::NavigateParams params(
       browser(), GURL(browse_to), ui::PAGE_TRANSITION_TYPED);
   params.disposition = CURRENT_TAB;
+
+  // This is needed to make the test
+  // MaterialHistoryBrowserTest.HistoryToolbarFocusTest pass on macOS. The test
+  // is fundamentally flawed, since it expects a particular widget to be
+  // focused. Chrome focus semantics are based on the Windows platform, where a
+  // widget cannot be focused without window activation. browser_tests can be

[sky, 2016/08/30 22:09:07]

interactive_ui_tests aren't sharded and are used when you need to test things
like system level activation. Should this test move there?

[erikchen, 2016/08/30 22:17:12]

Yes. I filed a bug against the team that wrote this test. Please see the crbug
linked in the comment: https://crbug.com/642467

+  // sharded, so there is no way to enforce that a given window is activated.
+  // Focus tests should be interactive_ui_tests, and they should explicitly
+  // activate the window. https://crbug.com/642467.
+  params.window_action = chrome::NavigateParams::SHOW_WINDOW;
+
   chrome::Navigate(&params);
   navigation_observer.Wait();
 }
 
 #if defined(ENABLE_PRINT_PREVIEW)
 
 // This custom ContentBrowserClient is used to get notified when a WebContents
 // for the print preview dialog gets created.
 class PrintContentBrowserClient : public ChromeContentBrowserClient {
  public:
@@ skipping 253 matching lines @@
 }
 
 GURL WebUIBrowserTest::WebUITestDataPathToURL(
     const base::FilePath::StringType& path) {
   base::FilePath dir_test_data;
   EXPECT_TRUE(PathService::Get(chrome::DIR_TEST_DATA, &dir_test_data));
   base::FilePath test_path(dir_test_data.Append(kWebUITestFolder).Append(path));
   EXPECT_TRUE(base::PathExists(test_path));
   return net::FilePathToFileURL(test_path);
 }