cc: Remove use of PassAs() and constructor-casting with scoped_ptr.

cc/resources/picture.cc

Index: cc/resources/picture.cc
diff --git a/cc/resources/picture.cc b/cc/resources/picture.cc
index ec1f333f1f251f098e51c83107e1652cdd91721e..6fa5abcabf203e4bfddcb99d3e72856155e98f3f 100644
--- a/cc/resources/picture.cc
+++ b/cc/resources/picture.cc
@@ -412,7 +412,7 @@ scoped_ptr<base::Value> Picture::AsValue() const {
   base::Base64Encode(std::string(serialized_picture.get(), serialized_size),
                      &b64_picture);
   res->SetString("skp64", b64_picture);
-  return res.PassAs<base::Value>();
+  return res.Pass();
 }
 
 void Picture::EmitTraceSnapshot() const {