[Chromecast] Turn CastContentWindow into an abstract interface.

chromecast/browser/test/cast_browser_test.cc

Index: chromecast/browser/test/cast_browser_test.cc
diff --git a/chromecast/browser/test/cast_browser_test.cc b/chromecast/browser/test/cast_browser_test.cc
index 781d2492fbbbb1ec114411537a371122f44242a8..9c2eb1a498f7a7b6e0972d248573a12200047d6d 100644
--- a/chromecast/browser/test/cast_browser_test.cc
+++ b/chromecast/browser/test/cast_browser_test.cc
@@ -59,11 +59,11 @@ void CastBrowserTest::RunTestOnMainThreadLoop() {
 }
 
 content::WebContents* CastBrowserTest::NavigateToURL(const GURL& url) {
-  window_ = base::MakeUnique<CastContentWindow>();
+  window_ = CastContentWindow::Create(this);
 
   web_contents_ = window_->CreateWebContents(
       CastBrowserProcess::GetInstance()->browser_context());
-  window_->CreateWindowTree(web_contents_.get());
+  window_->ShowWebContents(web_contents_.get());
   content::WaitForLoadStop(web_contents_.get());
 
   content::TestNavigationObserver same_tab_observer(web_contents_.get(), 1);
@@ -76,5 +76,11 @@ content::WebContents* CastBrowserTest::NavigateToURL(const GURL& url) {
   return web_contents_.get();
 }
 
+void CastBrowserTest::OnWindowDestroyed() {
+}
+
+void CastBrowserTest::OnKeyDown(ui::KeyboardCode keycode) {
+}
+
 }  // namespace shell
 }  // namespace chromecast