Fix webview example in views examples.

ash/test/ash_test_base.cc

Index: ash/test/ash_test_base.cc
diff --git a/ash/test/ash_test_base.cc b/ash/test/ash_test_base.cc
index ca7b9fc3908f8bd503f0a4fac8a69ac03961b17b..0e6b72b3e12ee0fb6fb7b347bc36836c2f418729 100644
--- a/ash/test/ash_test_base.cc
+++ b/ash/test/ash_test_base.cc
@@ -8,6 +8,7 @@
 
 #include "ash/shell.h"
 #include "ash/test/test_shell_delegate.h"
+#include "content/test/web_contents_tester.h"
 #include "ui/aura/env.h"
 #include "ui/aura/monitor_manager.h"
 #include "ui/aura/root_window.h"
@@ -18,6 +19,13 @@
 namespace ash {
 namespace test {
 
+content::WebContents* AshTestViewsDelegate::CreateWebContents(
+    content::BrowserContext* browser_context,
+    content::SiteInstance* site_instance) {
+  return content::WebContentsTester::CreateTestWebContents(browser_context,
+                                                           site_instance);
+}
+
 AshTestBase::AshTestBase() {
 }