Update ppapi/ to use scoped_refptr<T>::get() rather than implicit "operator T*"

ppapi/proxy/plugin_var_tracker.cc

Index: ppapi/proxy/plugin_var_tracker.cc
diff --git a/ppapi/proxy/plugin_var_tracker.cc b/ppapi/proxy/plugin_var_tracker.cc
index 0b583d6a3364d6b6281e2b0dde71ecdd9b49b21c..c3fac29014bf641504bc01c1975ab8f0c3095397 100644
--- a/ppapi/proxy/plugin_var_tracker.cc
+++ b/ppapi/proxy/plugin_var_tracker.cc
@@ -56,7 +56,7 @@ PP_Var PluginVarTracker::ReceiveObjectPassRef(const PP_Var& host_var,
     // two references on our behalf. We want to transfer that extra reference
     // to our list. This means we addref in the plugin, and release the extra
     // one in the renderer.
-    SendReleaseObjectMsg(*object);
+    SendReleaseObjectMsg(*object.get());
   }
   info.ref_count++;
   return ret;