Don't delete the invalid service id.

It was possible to put thing in a bad state by calling glBind* with an
invalid client id (which binds the invalid service id) and then calling
glDelete* with an invalid client id (which deletes the invald service
id).

BUG=785753

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I4628f964e9d14a1d87bc12b1cde3f056acb8314e
Reviewed-on: https://chromium-review.googlesource.com/791011Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519752}

gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc

@@ -65,8 +65,13 @@ error::Error DeleteHelper(GLsizei n,
     // Don't pass service IDs of objects with a client ID of 0.  They are
     // emulated and should not be deleteable
     if (client_id != 0) {
-      service_ids[ii] = id_map->GetServiceIDOrInvalid(client_id);
-      id_map->RemoveClientID(client_id);
+      ServiceType service_id = id_map->GetServiceIDOrInvalid(client_id);
+      // Don't delete the invalid service ID, if bind-generates-resource is
+      // enabled then it may be currently used as a placeholder
+      if (service_id != id_map->invalid_service_id()) {
+        DCHECK(service_id != 0);
+        id_map->RemoveClientID(client_id);
+    }
     }
   }