Pass the NetworkChangeNotifier to HostResolver.

This requires the following refactors:
  (1) NetworkChangeNotifier moves out of HttpNetworkSession into IOThread.
  (2) HostResolver gets initialized with NetworkChangeNotifier.
  (3) NetworkChangeNotifier needs to get passed into HttpCache and HttpNetworkSession (required updating a lot of files).
  (4) NetworkChangeNotifier is no longer reference counted.  It is owned by IOThread.
  (5) IOThread gains a new struct: Globals.  It can only be used on the io thread.
  (6) ChromeURLRequestContextFactory uses IOThread::Globals to initialize ChromeURLRequest objects with the host resolver and network change notifier.
BUG=26159

Review URL: http://codereview.chromium.org/552117

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@38052 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 59 insertions, 30 deletions

diff --git a/chrome/browser/io_thread.cc b/chrome/browser/io_thread.cc
index 82e2f50..da4bb20 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -15,11 +15,13 @@
 #include "net/base/host_cache.h"
 #include "net/base/host_resolver.h"
 #include "net/base/host_resolver_impl.h"
+#include "net/base/network_change_notifier.h"
 #include "net/url_request/url_request.h"
 
 namespace {
 
-net::HostResolver* CreateGlobalHostResolver() {
+net::HostResolver* CreateGlobalHostResolver(
+    net::NetworkChangeNotifier* network_change_notifier) {
   net::HostResolver* global_host_resolver = NULL;
 
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
@@ -31,7 +33,8 @@ net::HostResolver* CreateGlobalHostResolver() {
         command_line.GetSwitchValueASCII(switches::kFixedHost);
     global_host_resolver = new net::FixedHostResolver(host);
   } else {
-    global_host_resolver = net::CreateSystemHostResolver();
+    global_host_resolver =
+        net::CreateSystemHostResolver(network_change_notifier);
 
     if (command_line.HasSwitch(switches::kDisableIPv6))
       global_host_resolver->SetDefaultAddressFamily(net::ADDRESS_FAMILY_IPV4);
@@ -52,7 +55,7 @@ struct RunnableMethodTraits<IOThread> {
 
 IOThread::IOThread()
     : BrowserProcessSubThread(ChromeThread::IO),
-      host_resolver_(NULL),
+      globals_(NULL),
       prefetch_observer_(NULL),
       dns_master_(NULL) {}
 
@@ -60,11 +63,12 @@ IOThread::~IOThread() {
   // We cannot rely on our base class to stop the thread since we want our
   // CleanUp function to run.
   Stop();
+  DCHECK(!globals_);
 }
 
-net::HostResolver* IOThread::host_resolver() {
+IOThread::Globals* IOThread::globals() {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
-  return host_resolver_;
+  return globals_;
 }
 
 void IOThread::InitDnsMaster(
@@ -95,9 +99,13 @@ void IOThread::ChangedToOnTheRecord() {
 void IOThread::Init() {
   BrowserProcessSubThread::Init();
 
-  DCHECK(!host_resolver_);
-  host_resolver_ = CreateGlobalHostResolver();
-  host_resolver_->AddRef();
+  DCHECK(!globals_);
+  globals_ = new Globals;
+
+  globals_->network_change_notifier.reset(
+      net::NetworkChangeNotifier::CreateDefaultNetworkChangeNotifier());
+  globals_->host_resolver =
+      CreateGlobalHostResolver(globals_->network_change_notifier.get());
 }
 
 void IOThread::CleanUp() {
@@ -116,18 +124,16 @@ void IOThread::CleanUp() {
 
   // Not initialized in Init().  May not be initialized.
   if (prefetch_observer_) {
-    host_resolver_->RemoveObserver(prefetch_observer_);
+    globals_->host_resolver->RemoveObserver(prefetch_observer_);
     delete prefetch_observer_;
     prefetch_observer_ = NULL;
   }
 
   // TODO(eroman): temp hack for http://crbug.com/15513
-  host_resolver_->Shutdown();
+  globals_->host_resolver->Shutdown();
 
-  // TODO(willchan): Stop reference counting HostResolver.  It's owned by
-  // IOThread now.
-  host_resolver_->Release();
-  host_resolver_ = NULL;
+  delete globals_;
+  globals_ = NULL;
 
   // URLFetcher and URLRequest instances must NOT outlive the IO thread.
   //
@@ -157,12 +163,12 @@ void IOThread::InitDnsMasterOnIOThread(
   chrome_browser_net::EnableDnsPrefetch(prefetching_enabled);
 
   dns_master_ = new chrome_browser_net::DnsMaster(
-      host_resolver_, max_queue_delay, max_concurrent);
+      globals_->host_resolver, max_queue_delay, max_concurrent);
   dns_master_->AddRef();
 
   DCHECK(!prefetch_observer_);
   prefetch_observer_ = chrome_browser_net::CreatePrefetchObserver();
-  host_resolver_->AddObserver(prefetch_observer_);
+  globals_->host_resolver->AddObserver(prefetch_observer_);
 
   FinalizeDnsPrefetchInitialization(
       dns_master_, prefetch_observer_, hostnames_to_prefetch, referral_list);
@@ -178,9 +184,9 @@ void IOThread::ChangedToOnTheRecordOnIOThread() {
 
   // Clear the host cache to avoid showing entries from the OTR session
   // in about:net-internals.
-  if (host_resolver_->IsHostResolverImpl()) {
+  if (globals_->host_resolver->IsHostResolverImpl()) {
     net::HostCache* host_cache = static_cast<net::HostResolverImpl*>(
-        host_resolver_)->cache();
+        globals_->host_resolver.get())->cache();
     if (host_cache)
       host_cache->clear();
   }
diff --git a/chrome/browser/io_thread.h b/chrome/browser/io_thread.h
index f93f748..373d118 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -6,6 +6,8 @@
 #define CHROME_BROWSER_IO_THREAD_H_
 
 #include "base/basictypes.h"
+#include "base/ref_counted.h"
+#include "base/scoped_ptr.h"
 #include "base/task.h"
 #include "chrome/browser/browser_process_sub_thread.h"
 #include "chrome/common/net/dns.h"
@@ -17,13 +19,25 @@ namespace chrome_browser_net {
 class DnsMaster;
 }  // namespace chrome_browser_net
 
+namespace net {
+class NetworkChangeNotifier;
+}  // namespace net
+
 class IOThread : public BrowserProcessSubThread {
  public:
+  struct Globals {
+    scoped_ptr<net::NetworkChangeNotifier> network_change_notifier;
+    // TODO(willchan): Stop reference counting HostResolver.  It's owned by
+    // IOThread now.
+    scoped_refptr<net::HostResolver> host_resolver;
+  };
+
   IOThread();
 
   virtual ~IOThread();
 
-  net::HostResolver* host_resolver();
+  // Can only be called on the IO thread.
+  Globals* globals();
 
   // Initializes the DnsMaster.  |prefetching_enabled| indicates whether or
   // not dns prefetching should be enabled.  This should be called by the UI
@@ -56,10 +70,15 @@ class IOThread : public BrowserProcessSubThread {
   // These member variables are basically global, but their lifetimes are tied
   // to the IOThread.  IOThread owns them all, despite not using scoped_ptr.
   // This is because the destructor of IOThread runs on the wrong thread.  All
-  // member variables should be deleted in CleanUp().  Most of these will be
-  // initialized in Init().
+  // member variables should be deleted in CleanUp().
+
+  // These member variables are initialized in Init() and do not change for the
+  // lifetime of the IO thread.
+
+  Globals* globals_;
 
-  net::HostResolver* host_resolver_;
+  // These member variables are initialized by a task posted to the IO thread,
+  // which gets posted by calling certain member functions of IOThread.
 
   net::HostResolver::Observer* prefetch_observer_;
   chrome_browser_net::DnsMaster* dns_master_;
diff --git a/chrome/browser/net/chrome_url_request_context.cc b/chrome/browser/net/chrome_url_request_context.cc
index 8013800..a8349e8 100644
--- a/chrome/browser/net/chrome_url_request_context.cc
+++ b/chrome/browser/net/chrome_url_request_context.cc
@@ -141,7 +141,7 @@ ChromeURLRequestContext* FactoryForOriginal::Create() {
   ApplyProfileParametersToContext(context);
 
   // Global host resolver for the context.
-  context->set_host_resolver(io_thread()->host_resolver());
+  context->set_host_resolver(io_thread()->globals()->host_resolver);
 
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
@@ -152,7 +152,8 @@ ChromeURLRequestContext* FactoryForOriginal::Create() {
                          MessageLoop::current() /*io_loop*/));
 
   net::HttpCache* cache =
-      new net::HttpCache(context->host_resolver(),
+      new net::HttpCache(io_thread()->globals()->network_change_notifier.get(),
+                         context->host_resolver(),
                          context->proxy_service(),
                          context->ssl_config_service(),
                          disk_cache_path_, cache_size_);
@@ -262,7 +263,8 @@ ChromeURLRequestContext* FactoryForOffTheRecord::Create() {
   context->set_proxy_service(original_context->proxy_service());
 
   net::HttpCache* cache =
-      new net::HttpCache(context->host_resolver(), context->proxy_service(),
+      new net::HttpCache(io_thread()->globals()->network_change_notifier.get(),
+                         context->host_resolver(), context->proxy_service(),
                          context->ssl_config_service(), 0);
   context->set_cookie_store(new net::CookieMonster);
   context->set_cookie_policy(
@@ -371,10 +373,12 @@ ChromeURLRequestContext* FactoryForMedia::Create() {
   } else {
     // If original HttpCache doesn't exist, simply construct one with a whole
     // new set of network stack.
-    cache = new net::HttpCache(main_context->host_resolver(),
-                               main_context->proxy_service(),
-                               main_context->ssl_config_service(),
-                               disk_cache_path_, cache_size_);
+    cache = new net::HttpCache(
+        io_thread()->globals()->network_change_notifier.get(),
+        main_context->host_resolver(),
+        main_context->proxy_service(),
+        main_context->ssl_config_service(),
+        disk_cache_path_, cache_size_);
   }
 
   if (CommandLine::ForCurrentProcess()->HasSwitch(
diff --git a/chrome/browser/net/chrome_url_request_context.h b/chrome/browser/net/chrome_url_request_context.h
index f52029e..99aed21 100644
--- a/chrome/browser/net/chrome_url_request_context.h
+++ b/chrome/browser/net/chrome_url_request_context.h
@@ -10,6 +10,7 @@
 #include "net/base/cookie_policy.h"
 #include "chrome/browser/host_content_settings_map.h"
 #include "chrome/browser/host_zoom_map.h"
+#include "chrome/browser/io_thread.h"
 #include "chrome/browser/privacy_blacklist/blacklist.h"
 #include "chrome/browser/net/chrome_cookie_policy.h"
 #include "chrome/browser/net/url_request_context_getter.h"
@@ -28,7 +29,6 @@ class ProxyConfig;
 
 class ChromeURLRequestContext;
 class ChromeURLRequestContextFactory;
-class IOThread;
 
 // Subclass of URLRequestContext which can be used to store extra information
 // for requests.