Split ProxyResolverV8Tracing into an implementation and a wrapper.

net/proxy/proxy_resolver_v8_tracing_wrapper_unittest.cc

Index: net/proxy/proxy_resolver_v8_tracing_wrapper_unittest.cc
diff --git a/net/proxy/proxy_resolver_v8_tracing_wrapper_unittest.cc b/net/proxy/proxy_resolver_v8_tracing_wrapper_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f9fdca69151ccdd7e669581e1ac9c0a2ab11a557
--- /dev/null
+++ b/net/proxy/proxy_resolver_v8_tracing_wrapper_unittest.cc
@@ -0,0 +1,1146 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.

[eroman, 2015/06/26 15:37:25]

Any way to get this file to show up with better diffs? (as it draws from
proxy_resolver_v8_tracing_unittest.cc)

Maybe try re-uploading with "git cl upload --similarity=5" or some such thing.

I didn't review this file since there are too many diffs.

I am guessing this is a duplication of the original
proxy_resolver_v8_tracing_unittest.cc, so unlike the new
proxy_resolver_v8_tracing_unittest.cc it tests the netlog stuff?

Not thrilled about the duplication, but probably OK. Will get a better sense
when the diffs are cleaner, but we might simplify the testing. We can iterate on
this later.

[Sam McNally, 2015/06/29 01:33:51]

Done.
Yes.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/proxy/proxy_resolver_v8_tracing_wrapper.h"
+
+#include <string>
+
+#include "base/files/file_util.h"
+#include "base/message_loop/message_loop.h"
+#include "base/path_service.h"
+#include "base/stl_util.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/synchronization/waitable_event.h"
+#include "base/threading/platform_thread.h"
+#include "base/values.h"
+#include "net/base/net_errors.h"
+#include "net/base/test_completion_callback.h"
+#include "net/dns/host_cache.h"
+#include "net/dns/mock_host_resolver.h"
+#include "net/log/net_log.h"
+#include "net/log/test_net_log.h"
+#include "net/log/test_net_log_entry.h"
+#include "net/log/test_net_log_util.h"
+#include "net/proxy/proxy_info.h"
+#include "net/proxy/proxy_resolver_error_observer.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "url/gurl.h"
+
+namespace net {
+
+namespace {
+
+class ProxyResolverV8TracingWrapperTest : public testing::Test {
+ public:
+  void TearDown() override {
+    // Drain any pending messages, which may be left over from cancellation.
+    // This way they get reliably run as part of the current test, rather than
+    // spilling into the next test's execution.
+    base::MessageLoop::current()->RunUntilIdle();
+  }
+};
+
+scoped_refptr<ProxyResolverScriptData> LoadScriptData(const char* filename) {
+  base::FilePath path;
+  PathService::Get(base::DIR_SOURCE_ROOT, &path);
+  path = path.AppendASCII("net");
+  path = path.AppendASCII("data");
+  path = path.AppendASCII("proxy_resolver_v8_tracing_unittest");
+  path = path.AppendASCII(filename);
+
+  // Try to read the file from disk.
+  std::string file_contents;
+  bool ok = base::ReadFileToString(path, &file_contents);
+
+  // If we can't load the file from disk, something is misconfigured.
+  EXPECT_TRUE(ok) << "Failed to read file: " << path.value();
+
+  // Load the PAC script into the ProxyResolver.
+  return ProxyResolverScriptData::FromUTF8(file_contents);
+}
+
+scoped_ptr<ProxyResolverErrorObserver> ReturnErrorObserver(
+    scoped_ptr<ProxyResolverErrorObserver> error_observer) {
+  return error_observer;
+}
+
+scoped_ptr<ProxyResolver> CreateResolver(
+    NetLog* net_log,
+    HostResolver* host_resolver,
+    scoped_ptr<ProxyResolverErrorObserver> error_observer,
+    const char* filename) {
+  scoped_ptr<ProxyResolver> resolver;
+  ProxyResolverFactoryV8TracingWrapper factory(
+      host_resolver, net_log,
+      base::Bind(&ReturnErrorObserver, base::Passed(&error_observer)));
+  TestCompletionCallback callback;
+  scoped_ptr<ProxyResolverFactory::Request> request;
+  int rv = factory.CreateProxyResolver(LoadScriptData(filename), &resolver,
+                                       callback.callback(), &request);
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+  EXPECT_TRUE(resolver);
+  return resolver.Pass();
+}
+
+class MockErrorObserver : public ProxyResolverErrorObserver {
+ public:
+  MockErrorObserver() : event_(true, false) {}
+
+  void OnPACScriptError(int line_number, const base::string16& error) override {
+    {
+      base::AutoLock l(lock_);
+      output += base::StringPrintf("Error: line %d: %s\n", line_number,
+                                   base::UTF16ToASCII(error).c_str());
+    }
+    event_.Signal();
+  }
+
+  std::string GetOutput() {
+    base::AutoLock l(lock_);
+    return output;
+  }
+
+  void WaitForOutput() { event_.Wait(); }
+
+ private:
+  base::Lock lock_;
+  std::string output;
+
+  base::WaitableEvent event_;
+};
+
+TEST_F(ProxyResolverV8TracingWrapperTest, Simple) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      &log, &host_resolver, make_scoped_ptr(error_observer), "simple.js");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  EXPECT_EQ("foo:99", proxy_info.proxy_server().ToURI());
+
+  EXPECT_EQ(0u, host_resolver.num_resolve());
+
+  // There were no errors.
+  EXPECT_EQ("", error_observer->GetOutput());
+
+  // Check the NetLogs -- nothing was logged.
+  EXPECT_EQ(0u, log.GetSize());
+  EXPECT_EQ(0u, request_log.GetSize());
+}
+
+TEST_F(ProxyResolverV8TracingWrapperTest, JavascriptError) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      &log, &host_resolver, make_scoped_ptr(error_observer), "error.js");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://throw-an-error/"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(ERR_PAC_SCRIPT_FAILED, callback.WaitForResult());
+
+  EXPECT_EQ(0u, host_resolver.num_resolve());
+
+  EXPECT_EQ(
+      "Error: line 5: Uncaught TypeError: Cannot read property 'split' "
+      "of null\n",
+      error_observer->GetOutput());
+
+  // Check the NetLogs -- there was 1 alert and 1 javascript error, and they
+  // were output to both the global log, and per-request log.
+  TestNetLogEntry::List entries_list[2];
+  log.GetEntries(&entries_list[0]);
+  request_log.GetEntries(&entries_list[1]);
+
+  for (size_t list_i = 0; list_i < arraysize(entries_list); list_i++) {
+    const TestNetLogEntry::List& entries = entries_list[list_i];
+    EXPECT_EQ(2u, entries.size());
+    EXPECT_TRUE(LogContainsEvent(entries, 0, NetLog::TYPE_PAC_JAVASCRIPT_ALERT,
+                                 NetLog::PHASE_NONE));
+    EXPECT_TRUE(LogContainsEvent(entries, 1, NetLog::TYPE_PAC_JAVASCRIPT_ERROR,
+                                 NetLog::PHASE_NONE));
+
+    EXPECT_EQ("{\"message\":\"Prepare to DIE!\"}", entries[0].GetParamsJson());
+    EXPECT_EQ(
+        "{\"line_number\":5,\"message\":\"Uncaught TypeError: Cannot "
+        "read property 'split' of null\"}",
+        entries[1].GetParamsJson());
+  }
+}
+
+TEST_F(ProxyResolverV8TracingWrapperTest, TooManyAlerts) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  scoped_ptr<ProxyResolver> resolver =
+      CreateResolver(&log, &host_resolver, make_scoped_ptr(error_observer),
+                     "too_many_alerts.js");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  // Iteration1 does a DNS resolve
+  // Iteration2 exceeds the alert buffer
+  // Iteration3 runs in blocking mode and completes
+  EXPECT_EQ("foo:3", proxy_info.proxy_server().ToURI());
+
+  EXPECT_EQ(1u, host_resolver.num_resolve());
+
+  // No errors.
+  EXPECT_EQ("", error_observer->GetOutput());
+
+  // Check the NetLogs -- the script generated 50 alerts, which were mirrored
+  // to both the global and per-request logs.
+  TestNetLogEntry::List entries_list[2];
+  log.GetEntries(&entries_list[0]);
+  request_log.GetEntries(&entries_list[1]);
+
+  for (size_t list_i = 0; list_i < arraysize(entries_list); list_i++) {
+    const TestNetLogEntry::List& entries = entries_list[list_i];
+    EXPECT_EQ(50u, entries.size());
+    for (size_t i = 0; i < entries.size(); ++i) {
+      ASSERT_TRUE(LogContainsEvent(
+          entries, i, NetLog::TYPE_PAC_JAVASCRIPT_ALERT, NetLog::PHASE_NONE));
+    }
+  }
+}
+
+// Verify that buffered alerts cannot grow unboundedly, even when the message is
+// empty string.
+TEST_F(ProxyResolverV8TracingWrapperTest, TooManyEmptyAlerts) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  scoped_ptr<ProxyResolver> resolver =
+      CreateResolver(&log, &host_resolver, make_scoped_ptr(error_observer),
+                     "too_many_empty_alerts.js");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  EXPECT_EQ("foo:3", proxy_info.proxy_server().ToURI());
+
+  EXPECT_EQ(1u, host_resolver.num_resolve());
+
+  // No errors.
+  EXPECT_EQ("", error_observer->GetOutput());
+
+  // Check the NetLogs -- the script generated 50 alerts, which were mirrored
+  // to both the global and per-request logs.
+  TestNetLogEntry::List entries_list[2];
+  log.GetEntries(&entries_list[0]);
+  request_log.GetEntries(&entries_list[1]);
+
+  for (size_t list_i = 0; list_i < arraysize(entries_list); list_i++) {
+    const TestNetLogEntry::List& entries = entries_list[list_i];
+    EXPECT_EQ(1000u, entries.size());
+    for (size_t i = 0; i < entries.size(); ++i) {
+      ASSERT_TRUE(LogContainsEvent(
+          entries, i, NetLog::TYPE_PAC_JAVASCRIPT_ALERT, NetLog::PHASE_NONE));
+    }
+  }
+}
+
+// This test runs a PAC script that issues a sequence of DNS resolves. The test
+// verifies the final result, and that the underlying DNS resolver received
+// the correct set of queries.
+TEST_F(ProxyResolverV8TracingWrapperTest, Dns) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddRuleForAddressFamily("host1", ADDRESS_FAMILY_IPV4,
+                                                 "166.155.144.44");
+  host_resolver.rules()->AddIPLiteralRule("host1", "::1,192.168.1.1",
+                                          std::string());
+  host_resolver.rules()->AddSimulatedFailure("host2");
+  host_resolver.rules()->AddRule("host3", "166.155.144.33");
+  host_resolver.rules()->AddRule("host5", "166.155.144.55");
+  host_resolver.rules()->AddSimulatedFailure("host6");
+  host_resolver.rules()->AddRuleForAddressFamily("*", ADDRESS_FAMILY_IPV4,
+                                                 "122.133.144.155");
+  host_resolver.rules()->AddRule("*", "133.122.100.200");
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      &log, &host_resolver, make_scoped_ptr(error_observer), "dns.js");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  // The test does 13 DNS resolution, however only 7 of them are unique.
+  EXPECT_EQ(7u, host_resolver.num_resolve());
+
+  const char* kExpectedResult =
+      "122.133.144.155-"  // myIpAddress()
+      "null-"             // dnsResolve('')
+      "__1_192.168.1.1-"  // dnsResolveEx('host1')
+      "null-"             // dnsResolve('host2')
+      "166.155.144.33-"   // dnsResolve('host3')
+      "122.133.144.155-"  // myIpAddress()
+      "166.155.144.33-"   // dnsResolve('host3')
+      "__1_192.168.1.1-"  // dnsResolveEx('host1')
+      "122.133.144.155-"  // myIpAddress()
+      "null-"             // dnsResolve('host2')
+      "-"                 // dnsResolveEx('host6')
+      "133.122.100.200-"  // myIpAddressEx()
+      "166.155.144.44"    // dnsResolve('host1')
+      ":99";
+
+  EXPECT_EQ(kExpectedResult, proxy_info.proxy_server().ToURI());
+
+  // No errors.
+  EXPECT_EQ("", error_observer->GetOutput());
+
+  // Check the NetLogs -- the script generated 1 alert, mirrored to both
+  // the per-request and global logs.
+  TestNetLogEntry::List entries_list[2];
+  log.GetEntries(&entries_list[0]);
+  request_log.GetEntries(&entries_list[1]);
+
+  for (size_t list_i = 0; list_i < arraysize(entries_list); list_i++) {
+    const TestNetLogEntry::List& entries = entries_list[list_i];
+    EXPECT_EQ(1u, entries.size());
+    EXPECT_TRUE(LogContainsEvent(entries, 0, NetLog::TYPE_PAC_JAVASCRIPT_ALERT,
+                                 NetLog::PHASE_NONE));
+    EXPECT_EQ("{\"message\":\"iteration: 7\"}", entries[0].GetParamsJson());
+  }
+}
+
+// This test runs a PAC script that does "myIpAddress()" followed by
+// "dnsResolve()". This requires 2 restarts. However once the HostResolver's
+// cache is warmed, subsequent calls should take 0 restarts.
+TEST_F(ProxyResolverV8TracingWrapperTest, DnsChecksCache) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddRule("foopy", "166.155.144.11");
+  host_resolver.rules()->AddRule("*", "122.133.144.155");
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      &log, &host_resolver, make_scoped_ptr(error_observer), "simple_dns.js");
+
+  TestCompletionCallback callback1;
+  TestCompletionCallback callback2;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foopy/req1"), &proxy_info,
+                               callback1.callback(), NULL, request_log.bound());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback1.WaitForResult());
+
+  // The test does 2 DNS resolutions.
+  EXPECT_EQ(2u, host_resolver.num_resolve());
+
+  // The first request took 2 restarts, hence on g_iteration=3.
+  EXPECT_EQ("166.155.144.11:3", proxy_info.proxy_server().ToURI());
+
+  rv =
+      resolver->GetProxyForURL(GURL("http://foopy/req2"), &proxy_info,
+                               callback2.callback(), NULL, request_log.bound());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback2.WaitForResult());
+
+  EXPECT_EQ(4u, host_resolver.num_resolve());
+
+  // This time no restarts were required, so g_iteration incremented by 1.
+  EXPECT_EQ("166.155.144.11:4", proxy_info.proxy_server().ToURI());
+
+  // No errors.
+  EXPECT_EQ("", error_observer->GetOutput());
+
+  EXPECT_EQ(0u, log.GetSize());
+  EXPECT_EQ(0u, request_log.GetSize());
+}
+
+// This test runs a weird PAC script that was designed to defeat the DNS tracing
+// optimization. The proxy resolver should detect the inconsistency and
+// fall-back to synchronous mode execution.
+TEST_F(ProxyResolverV8TracingWrapperTest, FallBackToSynchronous1) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddRule("host1", "166.155.144.11");
+  host_resolver.rules()->AddRule("crazy4", "133.199.111.4");
+  host_resolver.rules()->AddRule("*", "122.133.144.155");
+
+  scoped_ptr<ProxyResolver> resolver =
+      CreateResolver(&log, &host_resolver, make_scoped_ptr(error_observer),
+                     "global_sideffects1.js");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  // The script itself only does 2 DNS resolves per execution, however it
+  // constructs the hostname using a global counter which changes on each
+  // invocation.
+  EXPECT_EQ(3u, host_resolver.num_resolve());
+
+  EXPECT_EQ("166.155.144.11-133.199.111.4:100",
+            proxy_info.proxy_server().ToURI());
+
+  // No errors.
+  EXPECT_EQ("", error_observer->GetOutput());
+
+  // Check the NetLogs -- the script generated 1 alert, mirrored to both
+  // the per-request and global logs.
+  TestNetLogEntry::List entries_list[2];
+  log.GetEntries(&entries_list[0]);
+  request_log.GetEntries(&entries_list[1]);
+
+  for (size_t list_i = 0; list_i < arraysize(entries_list); list_i++) {
+    const TestNetLogEntry::List& entries = entries_list[list_i];
+    EXPECT_EQ(1u, entries.size());
+    EXPECT_TRUE(LogContainsEvent(entries, 0, NetLog::TYPE_PAC_JAVASCRIPT_ALERT,
+                                 NetLog::PHASE_NONE));
+    EXPECT_EQ("{\"message\":\"iteration: 4\"}", entries[0].GetParamsJson());
+  }
+}
+
+// This test runs a weird PAC script that was designed to defeat the DNS tracing
+// optimization. The proxy resolver should detect the inconsistency and
+// fall-back to synchronous mode execution.
+TEST_F(ProxyResolverV8TracingWrapperTest, FallBackToSynchronous2) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddRule("host1", "166.155.144.11");
+  host_resolver.rules()->AddRule("host2", "166.155.144.22");
+  host_resolver.rules()->AddRule("host3", "166.155.144.33");
+  host_resolver.rules()->AddRule("host4", "166.155.144.44");
+  host_resolver.rules()->AddRule("*", "122.133.144.155");
+
+  scoped_ptr<ProxyResolver> resolver =
+      CreateResolver(&log, &host_resolver, make_scoped_ptr(error_observer),
+                     "global_sideffects2.js");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  EXPECT_EQ(3u, host_resolver.num_resolve());
+
+  EXPECT_EQ("166.155.144.44:100", proxy_info.proxy_server().ToURI());
+
+  // No errors.
+  EXPECT_EQ("", error_observer->GetOutput());
+
+  // Check the NetLogs -- nothing was logged.
+  EXPECT_EQ(0u, log.GetSize());
+  EXPECT_EQ(0u, request_log.GetSize());
+}
+
+// This test runs a weird PAC script that yields a never ending sequence
+// of DNS resolves when restarting. Running it will hit the maximum
+// DNS resolves per request limit (20) after which every DNS resolve will
+// fail.
+TEST_F(ProxyResolverV8TracingWrapperTest, InfiniteDNSSequence) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddRule("host*", "166.155.144.11");
+  host_resolver.rules()->AddRule("*", "122.133.144.155");
+
+  scoped_ptr<ProxyResolver> resolver =
+      CreateResolver(&log, &host_resolver, make_scoped_ptr(error_observer),
+                     "global_sideffects3.js");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  EXPECT_EQ(20u, host_resolver.num_resolve());
+
+  EXPECT_EQ(
+      "166.155.144.11-166.155.144.11-166.155.144.11-166.155.144.11-"
+      "166.155.144.11-166.155.144.11-166.155.144.11-166.155.144.11-"
+      "166.155.144.11-166.155.144.11-166.155.144.11-166.155.144.11-"
+      "166.155.144.11-166.155.144.11-166.155.144.11-166.155.144.11-"
+      "166.155.144.11-166.155.144.11-166.155.144.11-166.155.144.11-"
+      "null:21",
+      proxy_info.proxy_server().ToURI());
+
+  // No errors.
+  EXPECT_EQ("", error_observer->GetOutput());
+
+  // Check the NetLogs -- 1 alert was logged.
+  EXPECT_EQ(1u, log.GetSize());
+  EXPECT_EQ(1u, request_log.GetSize());
+}
+
+// This test runs a weird PAC script that yields a never ending sequence
+// of DNS resolves when restarting. Running it will hit the maximum
+// DNS resolves per request limit (20) after which every DNS resolve will
+// fail.
+TEST_F(ProxyResolverV8TracingWrapperTest, InfiniteDNSSequence2) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddRule("host*", "166.155.144.11");
+  host_resolver.rules()->AddRule("*", "122.133.144.155");
+
+  scoped_ptr<ProxyResolver> resolver =
+      CreateResolver(&log, &host_resolver, make_scoped_ptr(error_observer),
+                     "global_sideffects4.js");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  EXPECT_EQ(20u, host_resolver.num_resolve());
+
+  EXPECT_EQ("null21:34", proxy_info.proxy_server().ToURI());
+
+  // No errors.
+  EXPECT_EQ("", error_observer->GetOutput());
+
+  // Check the NetLogs -- 1 alert was logged.
+  EXPECT_EQ(1u, log.GetSize());
+  EXPECT_EQ(1u, request_log.GetSize());
+}
+
+void DnsDuringInitHelper(bool synchronous_host_resolver) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  host_resolver.set_synchronous_mode(synchronous_host_resolver);
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddRule("host1", "91.13.12.1");
+  host_resolver.rules()->AddRule("host2", "91.13.12.2");
+
+  scoped_ptr<ProxyResolver> resolver =
+      CreateResolver(&log, &host_resolver, make_scoped_ptr(error_observer),
+                     "dns_during_init.js");
+
+  // Initialization did 2 dnsResolves.
+  EXPECT_EQ(2u, host_resolver.num_resolve());
+
+  host_resolver.rules()->ClearRules();
+  host_resolver.GetHostCache()->clear();
+
+  host_resolver.rules()->AddRule("host1", "145.88.13.3");
+  host_resolver.rules()->AddRule("host2", "137.89.8.45");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  // Fetched host1 and host2 again, since the ones done during initialization
+  // should not have been cached.
+  EXPECT_EQ(4u, host_resolver.num_resolve());
+
+  EXPECT_EQ("91.13.12.1-91.13.12.2-145.88.13.3-137.89.8.45:99",
+            proxy_info.proxy_server().ToURI());
+
+  // Check the NetLogs -- the script generated 2 alerts during initialization.
+  EXPECT_EQ(0u, request_log.GetSize());
+  TestNetLogEntry::List entries;
+  log.GetEntries(&entries);
+
+  ASSERT_EQ(2u, entries.size());
+  EXPECT_TRUE(LogContainsEvent(entries, 0, NetLog::TYPE_PAC_JAVASCRIPT_ALERT,
+                               NetLog::PHASE_NONE));
+  EXPECT_TRUE(LogContainsEvent(entries, 1, NetLog::TYPE_PAC_JAVASCRIPT_ALERT,
+                               NetLog::PHASE_NONE));
+
+  EXPECT_EQ("{\"message\":\"Watsup\"}", entries[0].GetParamsJson());
+  EXPECT_EQ("{\"message\":\"Watsup2\"}", entries[1].GetParamsJson());
+}
+
+// Tests a PAC script which does DNS resolves during initialization.
+TEST_F(ProxyResolverV8TracingWrapperTest, DnsDuringInit) {
+  // Test with both both a host resolver that always completes asynchronously,
+  // and then again with one that completes synchronously.
+  DnsDuringInitHelper(false);
+  DnsDuringInitHelper(true);
+}
+
+void CrashCallback(int) {
+  // Be extra sure that if the callback ever gets invoked, the test will fail.
+  CHECK(false);
+}
+
+// Start some requests, cancel them all, and then destroy the resolver.
+// Note the execution order for this test can vary. Since multiple
+// threads are involved, the cancellation may be received a different
+// times.
+TEST_F(ProxyResolverV8TracingWrapperTest, CancelAll) {
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddSimulatedFailure("*");
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      nullptr, &host_resolver, make_scoped_ptr(error_observer), "dns.js");
+
+  const size_t kNumRequests = 5;
+  ProxyInfo proxy_info[kNumRequests];
+  ProxyResolver::RequestHandle request[kNumRequests];
+
+  for (size_t i = 0; i < kNumRequests; ++i) {
+    int rv = resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info[i],
+                                      base::Bind(&CrashCallback), &request[i],
+                                      BoundNetLog());
+    EXPECT_EQ(ERR_IO_PENDING, rv);
+  }
+
+  for (size_t i = 0; i < kNumRequests; ++i) {
+    resolver->CancelRequest(request[i]);
+  }
+}
+
+// Note the execution order for this test can vary. Since multiple
+// threads are involved, the cancellation may be received a different
+// times.
+TEST_F(ProxyResolverV8TracingWrapperTest, CancelSome) {
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddSimulatedFailure("*");
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      nullptr, &host_resolver, make_scoped_ptr(error_observer), "dns.js");
+
+  ProxyInfo proxy_info1;
+  ProxyInfo proxy_info2;
+  ProxyResolver::RequestHandle request1;
+  ProxyResolver::RequestHandle request2;
+  TestCompletionCallback callback;
+
+  int rv = resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info1,
+                                    base::Bind(&CrashCallback), &request1,
+                                    BoundNetLog());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+
+  rv = resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info2,
+                                callback.callback(), &request2, BoundNetLog());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+
+  resolver->CancelRequest(request1);
+
+  EXPECT_EQ(OK, callback.WaitForResult());
+}
+
+// Cancel a request after it has finished running on the worker thread, and has
+// posted a task the completion task back to origin thread.
+TEST_F(ProxyResolverV8TracingWrapperTest, CancelWhilePendingCompletionTask) {
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddSimulatedFailure("*");
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      nullptr, &host_resolver, make_scoped_ptr(error_observer), "error.js");
+
+  ProxyInfo proxy_info1;
+  ProxyInfo proxy_info2;
+  ProxyInfo proxy_info3;
+  ProxyResolver::RequestHandle request1;
+  ProxyResolver::RequestHandle request2;
+  ProxyResolver::RequestHandle request3;
+  TestCompletionCallback callback;
+
+  int rv = resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info1,
+                                    base::Bind(&CrashCallback), &request1,
+                                    BoundNetLog());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+
+  rv = resolver->GetProxyForURL(GURL("http://throw-an-error/"), &proxy_info2,
+                                callback.callback(), &request2, BoundNetLog());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+
+  // Wait until the first request has finished running on the worker thread.
+  // (The second request will output an error).
+  error_observer->WaitForOutput();
+
+  // Cancel the first request, while it has a pending completion task on
+  // the origin thread.
+  resolver->CancelRequest(request1);
+
+  EXPECT_EQ(ERR_PAC_SCRIPT_FAILED, callback.WaitForResult());
+
+  // Start another request, to make sure it is able to complete.
+  rv = resolver->GetProxyForURL(GURL("http://i-have-no-idea-what-im-doing/"),
+                                &proxy_info3, callback.callback(), &request3,
+                                BoundNetLog());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  EXPECT_EQ("i-approve-this-message:42", proxy_info3.proxy_server().ToURI());
+}
+
+// This implementation of HostResolver allows blocking until a resolve request
+// has been received. The resolve requests it receives will never be completed.
+class BlockableHostResolver : public HostResolver {
+ public:
+  BlockableHostResolver()
+      : num_cancelled_requests_(0), waiting_for_resolve_(false) {}
+
+  int Resolve(const RequestInfo& info,
+              RequestPriority priority,
+              AddressList* addresses,
+              const CompletionCallback& callback,
+              RequestHandle* out_req,
+              const BoundNetLog& net_log) override {
+    EXPECT_FALSE(callback.is_null());
+    EXPECT_TRUE(out_req);
+
+    if (!action_.is_null())
+      action_.Run();
+
+    // Indicate to the caller that a request was received.
+    EXPECT_TRUE(waiting_for_resolve_);
+    base::MessageLoop::current()->Quit();
+
+    // This line is intentionally after action_.Run(), since one of the
+    // tests does a cancellation inside of Resolve(), and it is more
+    // interesting if *out_req hasn't been written yet at that point.
+    *out_req = reinterpret_cast<RequestHandle*>(1);  // Magic value.
+
+    // Return ERR_IO_PENDING as this request will NEVER be completed.
+    // Expectation is for the caller to later cancel the request.
+    return ERR_IO_PENDING;
+  }
+
+  int ResolveFromCache(const RequestInfo& info,
+                       AddressList* addresses,
+                       const BoundNetLog& net_log) override {
+    NOTREACHED();
+    return ERR_DNS_CACHE_MISS;
+  }
+
+  void CancelRequest(RequestHandle req) override {
+    EXPECT_EQ(reinterpret_cast<RequestHandle*>(1), req);
+    num_cancelled_requests_++;
+  }
+
+  void SetAction(const base::Callback<void(void)>& action) { action_ = action; }
+
+  // Waits until Resolve() has been called.
+  void WaitUntilRequestIsReceived() {
+    waiting_for_resolve_ = true;
+    base::MessageLoop::current()->Run();
+    DCHECK(waiting_for_resolve_);
+    waiting_for_resolve_ = false;
+  }
+
+  int num_cancelled_requests() const { return num_cancelled_requests_; }
+
+ private:
+  int num_cancelled_requests_;
+  bool waiting_for_resolve_;
+  base::Callback<void(void)> action_;
+};
+
+// This cancellation test exercises a more predictable cancellation codepath --
+// when the request has an outstanding DNS request in flight.
+TEST_F(ProxyResolverV8TracingWrapperTest,
+       CancelWhileOutstandingNonBlockingDns) {
+  BlockableHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      nullptr, &host_resolver, make_scoped_ptr(error_observer), "dns.js");
+
+  ProxyInfo proxy_info1;
+  ProxyInfo proxy_info2;
+  ProxyResolver::RequestHandle request1;
+  ProxyResolver::RequestHandle request2;
+
+  int rv = resolver->GetProxyForURL(GURL("http://foo/req1"), &proxy_info1,
+                                    base::Bind(&CrashCallback), &request1,
+                                    BoundNetLog());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+
+  host_resolver.WaitUntilRequestIsReceived();
+
+  rv = resolver->GetProxyForURL(GURL("http://foo/req2"), &proxy_info2,
+                                base::Bind(&CrashCallback), &request2,
+                                BoundNetLog());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+
+  host_resolver.WaitUntilRequestIsReceived();
+
+  resolver->CancelRequest(request1);
+  resolver->CancelRequest(request2);
+
+  EXPECT_EQ(2, host_resolver.num_cancelled_requests());
+
+  // After leaving this scope, the ProxyResolver is destroyed.
+  // This should not cause any problems, as the outstanding work
+  // should have been cancelled.
+}
+
+void CancelRequestAndPause(ProxyResolver* resolver,
+                           ProxyResolver::RequestHandle request) {
+  resolver->CancelRequest(request);
+
+  // Sleep for a little bit. This makes it more likely for the worker
+  // thread to have returned from its call, and serves as a regression
+  // test for http://crbug.com/173373.
+  base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(30));
+}
+
+// In non-blocking mode, the worker thread actually does block for
+// a short time to see if the result is in the DNS cache. Test
+// cancellation while the worker thread is waiting on this event.
+TEST_F(ProxyResolverV8TracingWrapperTest, CancelWhileBlockedInNonBlockingDns) {
+  BlockableHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      nullptr, &host_resolver, make_scoped_ptr(error_observer), "dns.js");
+
+  ProxyInfo proxy_info;
+  ProxyResolver::RequestHandle request;
+
+  int rv = resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                                    base::Bind(&CrashCallback), &request,
+                                    BoundNetLog());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+
+  host_resolver.SetAction(
+      base::Bind(CancelRequestAndPause, resolver.get(), request));
+
+  host_resolver.WaitUntilRequestIsReceived();
+
+  // At this point the host resolver ran Resolve(), and should have cancelled
+  // the request.
+
+  EXPECT_EQ(1, host_resolver.num_cancelled_requests());
+}
+
+// Cancel the request while there is a pending DNS request, however before
+// the request is sent to the host resolver.
+TEST_F(ProxyResolverV8TracingWrapperTest, CancelWhileBlockedInNonBlockingDns2) {
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      nullptr, &host_resolver, make_scoped_ptr(error_observer), "dns.js");
+
+  ProxyInfo proxy_info;
+  ProxyResolver::RequestHandle request;
+
+  int rv = resolver->GetProxyForURL(GURL("http://foo/"), &proxy_info,
+                                    base::Bind(&CrashCallback), &request,
+                                    BoundNetLog());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+
+  // Wait a bit, so the DNS task has hopefully been posted. The test will
+  // work whatever the delay is here, but it is most useful if the delay
+  // is large enough to allow a task to be posted back.
+  base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(10));
+  resolver->CancelRequest(request);
+
+  EXPECT_EQ(0u, host_resolver.num_resolve());
+}
+
+TEST_F(ProxyResolverV8TracingWrapperTest,
+       CancelCreateResolverWhileOutstandingBlockingDns) {
+  BlockableHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  ProxyResolverFactoryV8TracingWrapper factory(
+      &host_resolver, nullptr,
+      base::Bind(&ReturnErrorObserver,
+                 base::Passed(make_scoped_ptr(error_observer))));
+
+  scoped_ptr<ProxyResolver> resolver;
+  scoped_ptr<ProxyResolverFactory::Request> request;
+  int rv = factory.CreateProxyResolver(LoadScriptData("dns_during_init.js"),
+                                       &resolver, base::Bind(&CrashCallback),
+                                       &request);
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+
+  host_resolver.WaitUntilRequestIsReceived();
+
+  request.reset();
+  EXPECT_EQ(1, host_resolver.num_cancelled_requests());
+}
+
+TEST_F(ProxyResolverV8TracingWrapperTest,
+       DeleteFactoryWhileOutstandingBlockingDns) {
+  BlockableHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  scoped_ptr<ProxyResolver> resolver;
+  scoped_ptr<ProxyResolverFactory::Request> request;
+  {
+    ProxyResolverFactoryV8TracingWrapper factory(
+        &host_resolver, nullptr,
+        base::Bind(&ReturnErrorObserver,
+                   base::Passed(make_scoped_ptr(error_observer))));
+
+    int rv = factory.CreateProxyResolver(LoadScriptData("dns_during_init.js"),
+                                         &resolver, base::Bind(&CrashCallback),
+                                         &request);
+    EXPECT_EQ(ERR_IO_PENDING, rv);
+    host_resolver.WaitUntilRequestIsReceived();
+  }
+  EXPECT_EQ(1, host_resolver.num_cancelled_requests());
+}
+
+TEST_F(ProxyResolverV8TracingWrapperTest, ErrorLoadingScript) {
+  BlockableHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  ProxyResolverFactoryV8TracingWrapper factory(
+      &host_resolver, nullptr,
+      base::Bind(&ReturnErrorObserver,
+                 base::Passed(make_scoped_ptr(error_observer))));
+
+  scoped_ptr<ProxyResolver> resolver;
+  scoped_ptr<ProxyResolverFactory::Request> request;
+  TestCompletionCallback callback;
+  int rv =
+      factory.CreateProxyResolver(LoadScriptData("error_on_load.js"), &resolver,
+                                  callback.callback(), &request);
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(ERR_PAC_SCRIPT_FAILED, callback.WaitForResult());
+  EXPECT_FALSE(resolver);
+}
+
+// This tests that the execution of a PAC script is terminated when the DNS
+// dependencies are missing. If the test fails, then it will hang.
+TEST_F(ProxyResolverV8TracingWrapperTest, Terminate) {
+  TestNetLog log;
+  BoundTestNetLog request_log;
+  MockCachingHostResolver host_resolver;
+  MockErrorObserver* error_observer = new MockErrorObserver;
+
+  host_resolver.rules()->AddRule("host1", "182.111.0.222");
+  host_resolver.rules()->AddRule("host2", "111.33.44.55");
+
+  scoped_ptr<ProxyResolver> resolver = CreateResolver(
+      &log, &host_resolver, make_scoped_ptr(error_observer), "terminate.js");
+
+  TestCompletionCallback callback;
+  ProxyInfo proxy_info;
+
+  int rv =
+      resolver->GetProxyForURL(GURL("http://foopy/req1"), &proxy_info,
+                               callback.callback(), NULL, request_log.bound());
+
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  // The test does 2 DNS resolutions.
+  EXPECT_EQ(2u, host_resolver.num_resolve());
+
+  EXPECT_EQ("foopy:3", proxy_info.proxy_server().ToURI());
+
+  // No errors.
+  EXPECT_EQ("", error_observer->GetOutput());
+
+  EXPECT_EQ(0u, log.GetSize());
+  EXPECT_EQ(0u, request_log.GetSize());
+}
+
+// Tests that multiple instances of ProxyResolverV8TracingWrapper can coexist
+// and run
+// correctly at the same time. This is relevant because at the moment (time
+// this test was written) each ProxyResolverV8TracingWrapper creates its own
+// thread to
+// run V8 on, however each thread is operating on the same v8::Isolate.
+TEST_F(ProxyResolverV8TracingWrapperTest, MultipleResolvers) {
+  // ------------------------
+  // Setup resolver0
+  // ------------------------
+  MockHostResolver host_resolver0;
+  host_resolver0.rules()->AddRuleForAddressFamily("host1", ADDRESS_FAMILY_IPV4,
+                                                  "166.155.144.44");
+  host_resolver0.rules()->AddIPLiteralRule("host1", "::1,192.168.1.1",
+                                           std::string());
+  host_resolver0.rules()->AddSimulatedFailure("host2");
+  host_resolver0.rules()->AddRule("host3", "166.155.144.33");
+  host_resolver0.rules()->AddRule("host5", "166.155.144.55");
+  host_resolver0.rules()->AddSimulatedFailure("host6");
+  host_resolver0.rules()->AddRuleForAddressFamily("*", ADDRESS_FAMILY_IPV4,
+                                                  "122.133.144.155");
+  host_resolver0.rules()->AddRule("*", "133.122.100.200");
+  scoped_ptr<ProxyResolver> resolver0 =
+      CreateResolver(nullptr, &host_resolver0,
+                     make_scoped_ptr(new MockErrorObserver), "dns.js");
+
+  // ------------------------
+  // Setup resolver1
+  // ------------------------
+  scoped_ptr<ProxyResolver> resolver1 =
+      CreateResolver(nullptr, &host_resolver0,
+                     make_scoped_ptr(new MockErrorObserver), "dns.js");
+
+  // ------------------------
+  // Setup resolver2
+  // ------------------------
+  scoped_ptr<ProxyResolver> resolver2 =
+      CreateResolver(nullptr, &host_resolver0,
+                     make_scoped_ptr(new MockErrorObserver), "simple.js");
+
+  // ------------------------
+  // Setup resolver3
+  // ------------------------
+  MockHostResolver host_resolver3;
+  host_resolver3.rules()->AddRule("foo", "166.155.144.33");
+  scoped_ptr<ProxyResolver> resolver3 =
+      CreateResolver(nullptr, &host_resolver3,
+                     make_scoped_ptr(new MockErrorObserver), "simple_dns.js");
+
+  // ------------------------
+  // Queue up work for each resolver (which will be running in parallel).
+  // ------------------------
+
+  ProxyResolver* resolver[] = {
+      resolver0.get(), resolver1.get(), resolver2.get(), resolver3.get(),
+  };
+
+  const size_t kNumResolvers = arraysize(resolver);
+  const size_t kNumIterations = 20;
+  const size_t kNumResults = kNumResolvers * kNumIterations;
+  TestCompletionCallback callback[kNumResults];
+  ProxyInfo proxy_info[kNumResults];
+
+  for (size_t i = 0; i < kNumResults; ++i) {
+    size_t resolver_i = i % kNumResolvers;
+    int rv = resolver[resolver_i]->GetProxyForURL(
+        GURL("http://foo/"), &proxy_info[i], callback[i].callback(), NULL,
+        BoundNetLog());
+    EXPECT_EQ(ERR_IO_PENDING, rv);
+  }
+
+  // ------------------------
+  // Verify all of the results.
+  // ------------------------
+
+  const char* kExpectedForDnsJs =
+      "122.133.144.155-"  // myIpAddress()
+      "null-"             // dnsResolve('')
+      "__1_192.168.1.1-"  // dnsResolveEx('host1')
+      "null-"             // dnsResolve('host2')
+      "166.155.144.33-"   // dnsResolve('host3')
+      "122.133.144.155-"  // myIpAddress()
+      "166.155.144.33-"   // dnsResolve('host3')
+      "__1_192.168.1.1-"  // dnsResolveEx('host1')
+      "122.133.144.155-"  // myIpAddress()
+      "null-"             // dnsResolve('host2')
+      "-"                 // dnsResolveEx('host6')
+      "133.122.100.200-"  // myIpAddressEx()
+      "166.155.144.44"    // dnsResolve('host1')
+      ":99";
+
+  for (size_t i = 0; i < kNumResults; ++i) {
+    size_t resolver_i = i % kNumResolvers;
+    EXPECT_EQ(OK, callback[i].WaitForResult());
+
+    std::string proxy_uri = proxy_info[i].proxy_server().ToURI();
+
+    if (resolver_i == 0 || resolver_i == 1) {
+      EXPECT_EQ(kExpectedForDnsJs, proxy_uri);
+    } else if (resolver_i == 2) {
+      EXPECT_EQ("foo:99", proxy_uri);
+    } else if (resolver_i == 3) {
+      EXPECT_EQ("166.155.144.33:",
+                proxy_uri.substr(0, proxy_uri.find(':') + 1));
+    } else {
+      NOTREACHED();
+    }
+  }
+}
+
+}  // namespace
+
+}  // namespace net