Hold a reference to object returned by GetGlobalHostResolver().

This change is to help diagnose bug 29038.

BUG=29038

Review URL: http://codereview.chromium.org/455025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@33510 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 16 insertions, 11 deletions

diff --git a/chrome/browser/net/dns_global.cc b/chrome/browser/net/dns_global.cc
index 970a529..c238a18 100644
--- a/chrome/browser/net/dns_global.cc
+++ b/chrome/browser/net/dns_global.cc
@@ -450,15 +450,19 @@ void EnsureDnsPrefetchShutdown() {
 
     // Stop observing DNS resolutions. Note that dns_master holds a reference
     // to the global host resolver, so is guaranteed to be live.
-    GetGlobalHostResolver()->RemoveObserver(&dns_resolution_observer);
+    global_host_resolver->RemoveObserver(&dns_resolution_observer);
+  }
 
+  if (global_host_resolver) {
     // TODO(eroman): temp hack for http://crbug.com/15513
-    GetGlobalHostResolver()->Shutdown();
-  }
+    global_host_resolver->Shutdown();
 
-  // TODO(eroman): This is a hack so the in process browser tests work if
-  // BrowserMain() is to be called again.
-  global_host_resolver = NULL;
+    global_host_resolver->Release();  // Balances GetGlobalHostResolver().
+
+    // TODO(eroman): This is a hack so the in process browser tests work if
+    // BrowserMain() is to be called again.
+    global_host_resolver = NULL;
+  }
 }
 
 void FreeDnsPrefetchResources() {
@@ -486,13 +490,14 @@ net::HostResolver* GetGlobalHostResolver() {
       std::string host_and_port =
           WideToASCII(command_line.GetSwitchValue(switches::kFixedServer));
       global_host_resolver = new net::FixedHostResolver(host_and_port);
-      return global_host_resolver;
-    }
+    } else {
+      global_host_resolver = net::CreateSystemHostResolver();
 
-    global_host_resolver = net::CreateSystemHostResolver();
+      if (command_line.HasSwitch(switches::kDisableIPv6))
+        global_host_resolver->SetDefaultAddressFamily(net::ADDRESS_FAMILY_IPV4);
+    }
 
-    if (command_line.HasSwitch(switches::kDisableIPv6))
-      global_host_resolver->SetDefaultAddressFamily(net::ADDRESS_FAMILY_IPV4);
+    global_host_resolver->AddRef();  // Balanced by EnsureDnsPrefetchShutdown().
   }
   return global_host_resolver;
 }