Add PepperTryCatch and V8ObjectVar classes

ppapi/shared_impl/var.cc

Index: ppapi/shared_impl/var.cc
diff --git a/ppapi/shared_impl/var.cc b/ppapi/shared_impl/var.cc
index 30201823ec13f4bd93529f4497362a5644c35f9d..195a5544dfe0553df92039c5e9b69baa390b44c2 100644
--- a/ppapi/shared_impl/var.cc
+++ b/ppapi/shared_impl/var.cc
@@ -82,6 +82,8 @@ ArrayBufferVar* Var::AsArrayBufferVar() { return NULL; }
 
 NPObjectVar* Var::AsNPObjectVar() { return NULL; }
 
+V8ObjectVar* Var::AsV8ObjectVar() { return NULL; }
+
 ProxyObjectVar* Var::AsProxyObjectVar() { return NULL; }
 
 ArrayVar* Var::AsArrayVar() { return NULL; }