MacViews: Fix ViewTest.HandleAccelerator by faking window activation

ui/views/test/views_test_base.h

 // 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.
 
 #ifndef UI_VIEWS_TEST_VIEWS_TEST_BASE_H_
 #define UI_VIEWS_TEST_VIEWS_TEST_BASE_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 16 matching lines @@
  public:
   ViewsTestBase();
   ~ViewsTestBase() override;
 
   // testing::Test:
   void SetUp() override;
   void TearDown() override;
 
   void RunPendingMessages();
 
+  // When using desktop widgets on Mac, window activation is asynchronous
+  // because the window server is involved. A window may also be deactivated by
+  // a test running in parallel, making it flaky. Calling this method permits a
+  // unit test to "fake" this activation, causing it to be synchronous and
+  // per-process instead. Note that window activation on X11 is also
+  // asynchronous, and on Windows another process may "steal" activation from a
+  // parallelized unit_test run. However, a test can use non-desktop widgets
+  // there instead.
+  void EnableMacFakeWindowActivation();
+
   // Creates a widget of |type| with any platform specific data for use in
   // cross-platform tests.
   Widget::InitParams CreateParams(Widget::InitParams::Type type);
 
  protected:
   TestViewsDelegate* views_delegate() const {
     return test_helper_->views_delegate();
   }
 
   void set_views_delegate(scoped_ptr<TestViewsDelegate> views_delegate) {
@@ skipping 17 matching lines @@
 #if defined(OS_WIN)
   ui::ScopedOleInitializer ole_initializer_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ViewsTestBase);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_TEST_VIEWS_TEST_BASE_H_