Introduce abstractions to allow embedders to test RenderViewHost

chrome/browser/ui/browser_list_unittest.cc

Index: chrome/browser/ui/browser_list_unittest.cc
diff --git a/chrome/browser/ui/browser_list_unittest.cc b/chrome/browser/ui/browser_list_unittest.cc
index fba764e168573a7ca0973ee98e80ecf67fe650f8..242a2a4c54de4b30913bd6098ad24303ff122f44 100644
--- a/chrome/browser/ui/browser_list_unittest.cc
+++ b/chrome/browser/ui/browser_list_unittest.cc
@@ -16,6 +16,7 @@
 #include "chrome/test/base/testing_pref_service.h"
 #include "chrome/test/base/testing_profile_manager.h"
 #include "content/public/browser/web_contents.h"
+#include "content/test/test_renderer_host.h"
 
 typedef BrowserWithTestWindowTest BrowserListTest;
 
@@ -31,7 +32,7 @@ size_t CountAllTabs() {
 
 // Helper function to navigate to the print preview page.
 void NavigateToPrintUrl(TabContentsWrapper* tab, int page_id) {
-  static_cast<content::TestRenderViewHost*>(
+  content::RenderViewHostTester::For(
       tab->web_contents()->GetRenderViewHost())->SendNavigate(
           page_id, GURL(chrome::kChromeUIPrintURL));
 }