MacViews: Split ViewEventTestBase into platform-specific files.

chrome/test/base/chrome_views_test_helper.h

+// 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.
+
+#ifndef CHROME_TEST_BASE_CHROME_VIEWS_TEST_HELPER_H_
+#define CHROME_TEST_BASE_CHROME_VIEWS_TEST_HELPER_H_
+
+#include "base/macros.h"
+#include "ui/gfx/native_widget_types.h"
+
+namespace ui {
+class ContextFactory;
+}
+
+// A helper class owned by tests that performs platform specific initialization.
+// ChromeViewsTestHelper behaves like views::ViewsTestHelper, but on ChromeOS it
+// will create an Ash shell environment, rather than using an AuraTestHelper.
+class ChromeViewsTestHelper {

[sky, 2014/08/06 17:37:44]

Can we name this better to indicate what it is for. Maybe something like
ViewsTestHelperInit or ViewsTestHelperPlatformInit?

[tapted, 2014/08/11 12:04:17]

I ended up with `ViewEventTestPlatFormPart*` - let me know what you think. I
think it's a good fit with the pattern in BrowserProcessPlatformPart.  (I
started using ..Init but it was feeling too much like a function name).

(in case it's useful, File moves are in patchset 4, so you can see most of the
diff for these files in a patchset 2:3 diff).

+ public:
+  virtual ~ChromeViewsTestHelper() {}
+
+  // Create a platform specific instance.
+  static ChromeViewsTestHelper* Create();
+
+  // Set up the platform-specific environment, returning the Ash root window on
+  // ash environments. Otherwise NULL.
+  virtual gfx::NativeWindow PlatformSetUp(

[sky, 2014/08/06 17:37:44]

Do we really need the two virtual methods? Can't Create() take the parameters
you have in PlatformSetUp() and the destructor do the tear down?

[tapted, 2014/08/11 12:04:17]

Done (mostly). There was code in view_event_test_base.cc between teardown and
the destructor before, but tests seem happy with the steps being merged (I was
initially worried they wouldn't be).

I still needed a `GetContext` function. I've left it as a virtual member
function, but a static function on the PlatformPart base class could also work.

+      ui::ContextFactory* context_factory) = 0;
+
+  // Tear down the platform-specific environment.
+  virtual void PlatformTearDown() = 0;
+
+ protected:
+  ChromeViewsTestHelper() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ChromeViewsTestHelper);
+};
+
+#endif  // CHROME_TEST_BASE_CHROME_VIEWS_TEST_HELPER_H_