Improve performance of proxy resolver by tracing DNS dependencies.

net/proxy/multi_threaded_proxy_resolver_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/multi_threaded_proxy_resolver.h"
 
 #include "base/message_loop.h"
 #include "base/stl_util.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
@@ skipping 48 matching lines @@
 
   virtual void CancelRequest(RequestHandle request) OVERRIDE {
     NOTREACHED();
   }
 
   virtual LoadState GetLoadState(RequestHandle request) const OVERRIDE {
     NOTREACHED();
     return LOAD_STATE_IDLE;
   }
 
-  virtual LoadState GetLoadStateThreadSafe(
-      RequestHandle request) const OVERRIDE {
-    NOTREACHED();
-    return LOAD_STATE_IDLE;
-  }
-
   virtual void CancelSetPacScript() OVERRIDE {
     NOTREACHED();
   }
 
   virtual int SetPacScript(
       const scoped_refptr<ProxyResolverScriptData>& script_data,
       const CompletionCallback& callback) OVERRIDE {
     CheckIsOnWorkerThread();
     last_script_data_ = script_data;
     return OK;
@@ skipping 98 matching lines @@
 
   virtual void CancelRequest(RequestHandle request) OVERRIDE {
     impl_->CancelRequest(request);
   }
 
   virtual LoadState GetLoadState(RequestHandle request) const OVERRIDE {
     NOTREACHED();
     return LOAD_STATE_IDLE;
   }
 
-  virtual LoadState GetLoadStateThreadSafe(
-      RequestHandle request) const OVERRIDE {
-    NOTREACHED();
-    return LOAD_STATE_IDLE;
-  }
-
   virtual void CancelSetPacScript() OVERRIDE {
     impl_->CancelSetPacScript();
   }
 
   virtual int SetPacScript(
       const scoped_refptr<ProxyResolverScriptData>& script_data,
       const CompletionCallback& callback) OVERRIDE {
     return impl_->SetPacScript(script_data, callback);
   }
 
@@ skipping 580 matching lines @@
   // All in all, the first thread should have seen just 1 request. And the
   // second thread 3 requests.
   ASSERT_EQ(2u, factory->resolvers().size());
   EXPECT_EQ(1, factory->resolvers()[0]->request_count());
   EXPECT_EQ(3, factory->resolvers()[1]->request_count());
 }
 
 }  // namespace
 
 }  // namespace net