remove some calls to to-be-deprecated v8::Value::To* functions

[email protected]
[email protected]
BUG=

Review URL: https://codereview.chromium.org/753523002

Cr-Commit-Position: refs/heads/master@{#305209}
diff --git a/content/renderer/pepper/ppb_var_deprecated_impl.cc b/content/renderer/pepper/ppb_var_deprecated_impl.cc
index c5a93e2..589981cf 100644
--- a/content/renderer/pepper/ppb_var_deprecated_impl.cc
+++ b/content/renderer/pepper/ppb_var_deprecated_impl.cc
@@ -235,7 +235,8 @@
   v8::Handle<v8::Object> recv =
       accessor.instance()->GetMainWorldContext()->Global();
   if (v8_method_name.As<v8::String>()->Length() != 0) {
-    function = function->Get(v8_method_name)->ToObject();
+    function = function->Get(v8_method_name)
+                   ->ToObject(accessor.instance()->GetIsolate());
     recv = accessor.GetObject();
   }