Introduce a delegate to avoid hardcoding "chrome-extension" in net/.

net/proxy/network_delegate_error_observer_unittest.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 "net/proxy/network_delegate_error_observer.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/message_loop_proxy.h"
 #include "base/threading/thread.h"
@@ skipping 58 matching lines @@
   }
   virtual bool OnCanSetCookie(const URLRequest& request,
                               const std::string& cookie_line,
                               CookieOptions* options) OVERRIDE {
     return true;
   }
   virtual bool OnCanAccessFile(const net::URLRequest& request,
                                const FilePath& path) const OVERRIDE {
     return true;
   }
+  virtual bool OnCanThrottleRequest(const URLRequest& request) const OVERRIDE {
+    return false;
+  }
 
   bool got_pac_error_;
 };
 
 }  // namespace
 
 // Check that the OnPACScriptError method can be called from an arbitrary
 // thread.
 TEST(NetworkDelegateErrorObserverTest, CallOnThread) {
   base::Thread thread("test_thread");
@@ skipping 20 matching lines @@
   thread.message_loop()->PostTask(
       FROM_HERE,
       base::Bind(&NetworkDelegateErrorObserver::OnPACScriptError,
                  base::Unretained(&observer), 42, string16()));
   thread.Stop();
   MessageLoop::current()->RunAllPending();
   // Shouldn't have crashed until here...
 }
 
 }  // namespace net