Fix the Declarative WebRequest API for <webview>

chrome/browser/guest_view/guest_view.h

Index: chrome/browser/guest_view/guest_view.h
diff --git a/chrome/browser/guest_view/guest_view.h b/chrome/browser/guest_view/guest_view.h
index 8afabce72e5802f8c398776eefe92eba4ad05795..fc88de8dd6be017c19ecab67f4ea0639fc466620 100644
--- a/chrome/browser/guest_view/guest_view.h
+++ b/chrome/browser/guest_view/guest_view.h
@@ -7,6 +7,9 @@
 
 #include "chrome/browser/guest_view/guest_view_base.h"
 
+// A GuestView is the templated base class for out-of-process frames in the
+// chrome layer. GuestView is templated on its derived type to allow for type-
+// safe access. See GuestViewBase for more information.
 template <typename T>
 class GuestView : public GuestViewBase {
  public: