Fix flaky win32 wifi provider test.

There was a race condition in provider startup; first call back might arrive before the listener was registerd.
This was previous hidden by fact that - until r37850 - an empty wifi result set was always condidered 'different' to another set and so it would create constant stream of update callbacks (hiding the fact the first one maybe missed)

BUG=http://crbug.com/34832
TEST=unit_tests.exe  --gtest_filter=Win32* --gtest_repeat=10000 --gtest_break_on_failure


Review URL: http://codereview.chromium.org/577047

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@38364 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 7 insertions, 5 deletions

diff --git a/chrome/browser/geolocation/device_data_provider.h b/chrome/browser/geolocation/device_data_provider.h
index 9463636..a03011b 100644
--- a/chrome/browser/geolocation/device_data_provider.h
+++ b/chrome/browser/geolocation/device_data_provider.h
@@ -296,6 +296,10 @@ class DeviceDataProvider {
     DCHECK(instance_);
     instance_->Ref();
     instance_->AddListener(listener);
+    // Start the provider after adding the listener, to avoid any race in
+    // it receiving an early callback.
+    bool started = instance_->impl_->StartDataProvider();
+    DCHECK(started);
     return instance_;
   }
 
@@ -327,8 +331,6 @@ class DeviceDataProvider {
     DCHECK(factory_function_);
     impl_.reset((*factory_function_)());
     impl_->SetContainer(this);
-    bool started = impl_->StartDataProvider();
-    DCHECK(started);
   }
   virtual ~DeviceDataProvider() {}
 
diff --git a/chrome/browser/geolocation/wifi_data_provider_unittest_win.cc b/chrome/browser/geolocation/wifi_data_provider_unittest_win.cc
index c97f417..c6a3b60 100644
--- a/chrome/browser/geolocation/wifi_data_provider_unittest_win.cc
+++ b/chrome/browser/geolocation/wifi_data_provider_unittest_win.cc
@@ -138,9 +138,9 @@ TEST_F(Win32WifiDataProviderTest, DoScanWithResults) {
   provider_->RemoveListener(&quit_listener);
 }
 
-TEST_F(Win32WifiDataProviderTest, DISABLED_StartThreadViaDeviceDataProvider) {
+TEST_F(Win32WifiDataProviderTest, StartThreadViaDeviceDataProvider) {
   MessageLoopQuitListener quit_listener(&main_message_loop_);
-  DeviceDataProvider<WifiData>::SetFactory(CreateWin32WifiDataProviderStatic);
+  WifiDataProvider::SetFactory(CreateWin32WifiDataProviderStatic);
   DeviceDataProvider<WifiData>::Register(&quit_listener);
   main_message_loop_.Run();
   DeviceDataProvider<WifiData>::Unregister(&quit_listener);
diff --git a/chrome/browser/geolocation/wifi_data_provider_win.cc b/chrome/browser/geolocation/wifi_data_provider_win.cc
index c8f9ff9..60a1e9b 100644
--- a/chrome/browser/geolocation/wifi_data_provider_win.cc
+++ b/chrome/browser/geolocation/wifi_data_provider_win.cc
@@ -155,7 +155,7 @@ bool GetSystemDirectory(string16 *path);
 }  // namespace
 
 template<>
-WifiDataProviderImplBase *WifiDataProvider::DefaultFactoryFunction() {
+WifiDataProviderImplBase* WifiDataProvider::DefaultFactoryFunction() {
   return new Win32WifiDataProvider();
 }