Prevent making real DNS lookups by chrome tests.

chrome/browser/net/dns_master_unittest.cc

 // Copyright (c) 2006-2008 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 <time.h>
 
 #include <algorithm>
 #include <sstream>
 #include <string>
 
@@ skipping 64 matching lines @@
   }
 
   void WaitForResolution(DnsMaster* master, const NameList& hosts) {
     HelperTimer* timer = new HelperTimer();
     timer->Start(TimeDelta::FromMilliseconds(100),
                  new WaitForResolutionHelper(master, hosts, timer),
                  &WaitForResolutionHelper::Run);
     MessageLoop::current()->Run();
   }
 
+  scoped_refptr<net::RuleBasedHostMapper> mapper_;
+
  private:
   MessageLoop loop;
-  scoped_refptr<net::RuleBasedHostMapper> mapper_;
   net::ScopedHostMapper scoped_mapper_;
 };
 
 //------------------------------------------------------------------------------
 // Provide a function to create unique (nonexistant) domains at *every* call.
 //------------------------------------------------------------------------------
 static std::string GetNonexistantDomain() {
   static std::string postfix = ".google.com";
   static std::string prefix = "www.";
   static std::string mid = "datecount";
@@ skipping 16 matching lines @@
     resolver.Resolve(hostname, 80, &addresses, NULL);
 
     return Time::Now() - start;
 }
 
 //------------------------------------------------------------------------------
 
 // First test to be sure the OS is caching lookups, which is the whole premise
 // of DNS prefetching.
 TEST_F(DnsMasterTest, OsCachesLookupsTest) {
+  mapper_->AllowDirectLookup("*.google.com");
+
   const Time start = Time::Now();
   int all_lookups = 0;
   int lookups_with_improvement = 0;
   // This test can be really flaky on Linux. It should run in much shorter time,
   // but sometimes it won't and we don't like bogus failures.
   while (Time::Now() - start < TimeDelta::FromMinutes(1)) {
     std::string badname;
     badname = GetNonexistantDomain();
 
     TimeDelta duration = BlockingDnsLookup(badname);
@@ skipping 132 matching lines @@
 
   EXPECT_GT(testing_master.peak_pending_lookups(), names.size() / 2);
   EXPECT_LE(testing_master.peak_pending_lookups(), names.size());
   EXPECT_LE(testing_master.peak_pending_lookups(),
             DnsMaster::kMaxConcurrentLookups);
 
   testing_master.Shutdown();
 }
 
 TEST_F(DnsMasterTest, ConcurrentLookupTest) {
+  mapper_->AddSimulatedFailure("*.notfound");
+
   DnsMaster testing_master;
 
   std::string goog("www.google.com"),
     goog2("gmail.google.com.com"),
     goog3("mail.google.com"),
     goog4("gmail.com");
-  std::string bad1(GetNonexistantDomain()),
-    bad2(GetNonexistantDomain());
+  std::string bad1("bad1.notfound"),
+    bad2("bad2.notfound");
 
   NameList names;
   names.insert(names.end(), goog);
   names.insert(names.end(), goog3);
   names.insert(names.end(), bad1);
   names.insert(names.end(), goog2);
   names.insert(names.end(), bad2);
   names.insert(names.end(), goog4);
   names.insert(names.end(), goog);
 
@@ skipping 23 matching lines @@
 
   EXPECT_GT(testing_master.peak_pending_lookups(), names.size() / 2);
   EXPECT_LE(testing_master.peak_pending_lookups(), names.size());
   EXPECT_LE(testing_master.peak_pending_lookups(),
             DnsMaster::kMaxConcurrentLookups);
 
   testing_master.Shutdown();
 }
 
 TEST_F(DnsMasterTest, MassiveConcurrentLookupTest) {
+  mapper_->AddSimulatedFailure("*.notfound");
+
   DnsMaster testing_master;
 
   NameList names;
   for (int i = 0; i < 100; i++)
-    names.push_back(GetNonexistantDomain());
+    names.push_back("host" + IntToString(i) + ".notfound");
 
   // Try to flood the master with many concurrent requests.
   for (int i = 0; i < 10; i++)
     testing_master.ResolveList(names, DnsHostInfo::PAGE_SCAN_MOTIVATED);
 
   WaitForResolution(&testing_master, names);
 
   MessageLoop::current()->RunAllPending();
 
   EXPECT_LE(testing_master.peak_pending_lookups(), names.size());
@@ skipping 186 matching lines @@
                                         recovered_referral_list));
   EXPECT_EQ(kLatencyNotFound,
             GetLatencyFromSerialization(motivation_hostname,
                                         img_subresource_hostname,
                                         recovered_referral_list));
 
   master.Shutdown();
 }
 
 }  // namespace chrome_browser_net