Massively simplify the NetworkChangeNotifier infrastructure:...

net/base/host_resolver_impl.cc

 // Copyright (c) 2010 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/base/host_resolver_impl.h"
 
 #if defined(OS_WIN)
 #include <Winsock2.h>
 #elif defined(OS_POSIX)
 #include <netdb.h>
@@ skipping 11 matching lines @@
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
 #include "base/time.h"
 #include "base/values.h"
 #include "base/worker_pool.h"
 #include "net/base/address_list.h"
 #include "net/base/host_resolver_proc.h"
 #include "net/base/net_log.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
-#include "net/base/network_change_notifier.h"
 
 #if defined(OS_WIN)
 #include "net/base/winsock_init.h"
 #endif
 
 namespace net {
 
 namespace {
 
 HostCache* CreateDefaultCache() {
   static const size_t kMaxHostCacheEntries = 100;
 
   HostCache* cache = new HostCache(
       kMaxHostCacheEntries,
       base::TimeDelta::FromMinutes(1),
       base::TimeDelta::FromSeconds(0));  // Disable caching of failed DNS.
 
   return cache;
 }
 
 }  // anonymous namespace
 
-HostResolver* CreateSystemHostResolver(
-    NetworkChangeNotifier* network_change_notifier) {
+HostResolver* CreateSystemHostResolver() {
   // Maximum of 50 concurrent threads.
   // TODO(eroman): Adjust this, do some A/B experiments.
   static const size_t kMaxJobs = 50u;
 
-  HostResolverImpl* resolver = new HostResolverImpl(
-      NULL, CreateDefaultCache(), network_change_notifier, kMaxJobs);
+  HostResolverImpl* resolver =
+      new HostResolverImpl(NULL, CreateDefaultCache(), kMaxJobs);
 
   return resolver;
 }
 
 static int ResolveAddrInfo(HostResolverProc* resolver_proc,
                            const std::string& host,
                            AddressFamily address_family,
                            HostResolverFlags host_resolver_flags,
                            AddressList* out,
                            int* os_error) {
@@ skipping 624 matching lines @@
 
   // The requests which are waiting to be started for this pool.
   PendingRequestsQueue pending_requests_[NUM_PRIORITIES];
 };
 
 //-----------------------------------------------------------------------------
 
 HostResolverImpl::HostResolverImpl(
     HostResolverProc* resolver_proc,
     HostCache* cache,
-    NetworkChangeNotifier* network_change_notifier,
     size_t max_jobs)
     : cache_(cache),
       max_jobs_(max_jobs),
       next_request_id_(0),
       next_job_id_(0),
       resolver_proc_(resolver_proc),
       default_address_family_(ADDRESS_FAMILY_UNSPECIFIED),
       shutdown_(false),
-      network_change_notifier_(network_change_notifier),
       ipv6_probe_monitoring_(false) {
   DCHECK_GT(max_jobs, 0u);
 
   // It is cumbersome to expose all of the constraints in the constructor,
   // so we choose some defaults, which users can override later.
   job_pools_[POOL_NORMAL] = new JobPool(max_jobs, 100u * max_jobs);
 
 #if defined(OS_WIN)
   EnsureWinsockInit();
 #endif
-  if (network_change_notifier_)
-    network_change_notifier_->AddObserver(this);
+  NetworkChangeNotifier::AddObserver(this);
 }
 
 HostResolverImpl::~HostResolverImpl() {
   // Cancel the outstanding jobs. Those jobs may contain several attached
   // requests, which will also be cancelled.
   DiscardIPv6ProbeJob();
 
   for (JobMap::iterator it = jobs_.begin(); it != jobs_.end(); ++it)
     it->second->Cancel();
 
   // In case we are being deleted during the processing of a callback.
   if (cur_completing_job_)
     cur_completing_job_->Cancel();
 
-  if (network_change_notifier_)
-    network_change_notifier_->RemoveObserver(this);
+  NetworkChangeNotifier::RemoveObserver(this);
 
   // Delete the job pools.
   for (size_t i = 0u; i < arraysize(job_pools_); ++i)
     delete job_pools_[i];
 }
 
 // TODO(eroman): Don't create cache entries for hostnames which are simply IP
 // address literals.
 int HostResolverImpl::Resolve(const RequestInfo& info,
                               AddressList* addresses,
@@ skipping 399 matching lines @@
     if (r == req)
       return error;
 
     r->OnComplete(error, AddressList());
   }
 
   return ERR_IO_PENDING;
 }
 
 }  // namespace net