Proxy PPB_Var, fix o-o-p string var id tracking.

ppapi/tests/test_var_deprecated.cc

Index: ppapi/tests/test_var_deprecated.cc
diff --git a/ppapi/tests/test_var_deprecated.cc b/ppapi/tests/test_var_deprecated.cc
index 7b77b18054446750dc49733726c19d8edfb11818..d2e2e3d86f8f3d02d80c68dab132838ce8f8a711 100644
--- a/ppapi/tests/test_var_deprecated.cc
+++ b/ppapi/tests/test_var_deprecated.cc
@@ -106,15 +106,9 @@ std::string TestVarDeprecated::TestBasicString() {
 
     // Destroy the string, readback should now fail.
     var_interface_->Release(str);
-    /*
-    Note: this will crash in the current out-of-process implementation since
-    we don't do actual tracking of strings (we just convert the ID to a
-    pointer).
-    TODO(brettw) This should be fixed and this checking code re-enabled.
     result = var_interface_->VarToUtf8(str, &len);
     ASSERT_EQ(0, len);
     ASSERT_EQ(NULL, result);
-    */
   }
 
   // Make sure nothing leaked.