RenderWidgetHostViewChildFrame's called a virtual in its ctor.

content/browser/frame_host/render_widget_host_view_guest_unittest.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 "content/browser/frame_host/render_widget_host_view_guest.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/macros.h"
@@ skipping 52 matching lines @@
     ContextProviderFactoryImpl::Initialize(&gpu_channel_factory_);
     ui::ContextProviderFactory::SetInstance(
         ContextProviderFactoryImpl::GetInstance());
 #endif
     browser_context_.reset(new TestBrowserContext);
     MockRenderProcessHost* process_host =
         new MockRenderProcessHost(browser_context_.get());
     int32_t routing_id = process_host->GetNextRoutingID();
     widget_host_ =
         new RenderWidgetHostImpl(&delegate_, process_host, routing_id, false);
-    view_ = new RenderWidgetHostViewGuest(
+    view_ = RenderWidgetHostViewGuest::Create(
         widget_host_, NULL,
         (new TestRenderWidgetHostView(widget_host_))->GetWeakPtr());
   }
 
   void TearDown() override {
     if (view_)
       view_->Destroy();
     delete widget_host_;
 
     browser_context_.reset();
@@ skipping 99 matching lines @@
         new MockRenderProcessHost(browser_context_.get());
     web_contents_.reset(
         TestWebContents::Create(browser_context_.get(), nullptr));
     // We don't own the BPG, the WebContents does.
     browser_plugin_guest_ = new TestBrowserPluginGuest(
         web_contents_.get(), &browser_plugin_guest_delegate_);
 
     int32_t routing_id = process_host->GetNextRoutingID();
     widget_host_ =
         new RenderWidgetHostImpl(&delegate_, process_host, routing_id, false);
-    view_ = new RenderWidgetHostViewGuest(
+    view_ = RenderWidgetHostViewGuest::Create(
         widget_host_, browser_plugin_guest_,
         (new TestRenderWidgetHostView(widget_host_))->GetWeakPtr());
   }
 
   void TearDown() override {
     if (view_)
       view_->Destroy();
     delete widget_host_;
 
     // It's important to make sure that the view finishes destructing before
@@ skipping 107 matching lines @@
 
   browser_plugin_guest_->set_attached(false);
   browser_plugin_guest_->ResetTestData();
 
   view_->OnSwapCompositorFrame(
       0, CreateDelegatedFrame(scale_factor, view_size, view_rect));
   EXPECT_TRUE(surface_id().is_null());
 }
 
 }  // namespace content