Re-implement the screensaver to use WebView instead of ExtensionDialogHost.

ui/views/views_delegate.h

Index: ui/views/views_delegate.h
diff --git a/ui/views/views_delegate.h b/ui/views/views_delegate.h
index d1fc739e3c791bf530af40849dbf842322768e2d..11e38f5ed968c96f9b67d47d2ed00844d11c070e 100644
--- a/ui/views/views_delegate.h
+++ b/ui/views/views_delegate.h
@@ -17,6 +17,12 @@
 #include "ui/base/ui_base_types.h"
 #include "ui/views/views_export.h"
 
+namespace content {
+class WebContents;
+class BrowserContext;
+class SiteInstance;
+}
+
 namespace gfx {
 class Rect;
 }
@@ -108,6 +114,11 @@ class VIEWS_EXPORT ViewsDelegate {
   virtual NativeWidgetHelperAura* CreateNativeWidgetHelper(
       NativeWidgetAura* native_widget) = 0;
 #endif
+
+  // Creates a web contents. This will return NULL unless overriden.
+  virtual content::WebContents* CreateWebContents(
+      content::BrowserContext* browser_context,
+      content::SiteInstance* site_instance) = 0;
 };
 
 }  // namespace views