Improve unit testing of socket API.

chrome/browser/extensions/api/socket/socket_api.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/socket/socket_api.h"
 
 #include "base/bind.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/api/dns/host_resolver_wrapper.h"
 #include "chrome/browser/extensions/api/socket/socket.h"
@@ skipping 24 matching lines @@
 
 SocketAsyncApiFunction::SocketAsyncApiFunction()
     : manager_(NULL) {
 }
 
 SocketAsyncApiFunction::~SocketAsyncApiFunction() {
 }
 
 bool SocketAsyncApiFunction::PrePrepare() {
   manager_ = ExtensionSystem::Get(profile())->socket_manager();
+  DCHECK(manager_) << "There is no socket manager. " <<
+      "It is likely you are testing this API in an isolated environment.";

[asargent_no_longer_on_chrome, 2012/07/23 16:57:57]

nit: I think this second line of error output is probably unnecessary. If you
want to keep it, a suggested change would be to something like "If you are using
this object in a test, you need to provide a socket manager implementation"

   return manager_ != NULL;
 }
 
 bool SocketAsyncApiFunction::Respond() {
   return error_.empty();
 }
 
 SocketExtensionWithDnsLookupFunction::SocketExtensionWithDnsLookupFunction()
     : io_thread_(g_browser_process->io_thread()),
       request_handle_(new net::HostResolver::RequestHandle),
@@ skipping 385 matching lines @@
   bool result = false;
   Socket* socket = manager_->Get(params_->socket_id);
   if (socket)
     result = socket->SetNoDelay(params_->no_delay);
   else
     error_ = kSocketNotFoundError;
   SetResult(Value::CreateBooleanValue(result));
 }
 
 }  // namespace extensions