net/proxy_resolution/proxy_resolver_v8_tracing_wrapper.cc is no longer referenced by anything but its own tests, and should be removed.

However, proxy_resolver_v8_tracing_wrapper_unittest.cc is providing some coverage for ProxyResolverFactoryV8Tracing, which is still used. Before removing ProxyResolverFactoryV8TracingWrapper the tests will need to be merged into proxy_resolver_v8_tracing_unittest.cc and cleaned up to remove duplicates and expectations that are no longer relevant.