Convert FileRefImpl and URLRequestInfo to shared_impl.

ppapi/shared_impl/scoped_pp_resource.h

Index: ppapi/shared_impl/scoped_pp_resource.h
diff --git a/ppapi/shared_impl/scoped_pp_resource.h b/ppapi/shared_impl/scoped_pp_resource.h
index 74cb9eb2d8cf853f1f17b4c0922e1a3cad872e2b..96db4ee1414ae9d84152152ee515dd4c33517578 100644
--- a/ppapi/shared_impl/scoped_pp_resource.h
+++ b/ppapi/shared_impl/scoped_pp_resource.h
@@ -14,11 +14,16 @@ class Resource;
 // This is a version of scoped_refptr but for PP_Resources.
 class ScopedPPResource {
  public:
+  struct PassRef {};
+
   ScopedPPResource();
 
   // Takes one reference to the given resource.
   explicit ScopedPPResource(PP_Resource resource);
 
+  // Assumes responsibility for one ref that the resource already has.
+  explicit ScopedPPResource(const PassRef&, PP_Resource resource);
+
   // Helper to get the PP_Resource out of the given object and take a reference
   // to it.
   explicit ScopedPPResource(Resource* resource);