Backfill some UI tests.

content/public/test/test_renderer_host.cc

 // 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.
 
 #include "content/public/test/test_renderer_host.h"
 
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
@@ skipping 263 matching lines @@
   aura_test_helper_->SetUp(context_factory, context_factory_private);
   new wm::DefaultActivationClient(aura_test_helper_->root_window());
 #endif
 
   sanity_checker_.reset(new ContentBrowserSanityChecker());
 
   DCHECK(!browser_context_);
   browser_context_.reset(CreateBrowserContext());
 
   SetContents(CreateTestWebContents());
+#if defined(USE_AURA)
+  static_cast<content::TestRenderWidgetHostView*>(
+      web_contents()->GetRenderWidgetHostView())
+      ->set_native_view(aura_test_helper_->root_window());

[sky, 2017/05/07 22:44:23]

This is confusing as you're setting the aura::Window created by AuraTestHelper
as the native view of the RenderWidgetHostView. My initial reaction is doing
that is confusing and easily misused. What about creating an aura::Window and
having TestRenderViewHost own it? You could parent the window to
AuraTestHelper's window if necessary.

[Bret, 2017/05/09 23:44:42]

Okay I made TestRenderWidgetHostView a WindowDelegate and it creates its own
Window, and that works. I guess it's not important that the Window actually does
anything, just that it exists.

+#endif
 
   if (IsBrowserSideNavigationEnabled())
     BrowserSideNavigationSetUp();
 }
 
 void RenderViewHostTestHarness::TearDown() {
   if (IsBrowserSideNavigationEnabled())
     BrowserSideNavigationTearDown();
 
   SetContents(NULL);
@@ skipping 31 matching lines @@
 
 void RenderViewHostTestHarness::SetRenderProcessHostFactory(
     RenderProcessHostFactory* factory) {
   if (rvh_test_enabler_)
     rvh_test_enabler_->rvh_factory_->set_render_process_host_factory(factory);
   else
     factory_ = factory;
 }
 
 }  // namespace content