Bug 978709 - 2.b/6: don't use nsIRILDataCallback in GonkGPSGeolocationProvider. r=kanru

nsIRILDataCallback has been abused in RadioInterfaceLayer.js and is
becoming an RIL internal utility.  Besides, nsIRILDataCallback has
also racing problem as described in bug 976897.  We should really use
NetworkManager observer events to replace the notification mechanism
here.

dom/system/gonk/GonkGPSGeolocationProvider.cpp

@@ -19,9 +19,11 @@
 
 #include "GonkGPSGeolocationProvider.h"
 #include "mozilla/Preferences.h"
+#include "mozilla/Services.h"
 #include "nsGeoPosition.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsINetworkManager.h"
+#include "nsIObserverService.h"
 #include "nsJSUtils.h"
 #include "nsServiceManagerUtils.h"
 #include "nsThreadUtils.h"
@@ -44,17 +46,20 @@ using namespace mozilla;
 
 static const int kDefaultPeriod = 1000; // ms
 
+static const char* kNetworkConnStateChangedTopic = "network-connection-state-changed";
+
 // While most methods of GonkGPSGeolocationProvider should only be
 // called from main thread, we deliberately put the Init and ShutdownGPS
 // methods off main thread to avoid blocking.
 #ifdef MOZ_B2G_RIL
 NS_IMPL_ISUPPORTS3(GonkGPSGeolocationProvider,
                    nsIGeolocationProvider,
-                   nsIRILDataCallback,
+                   nsIObserver,
                    nsISettingsServiceCallback)
 #else
-NS_IMPL_ISUPPORTS1(GonkGPSGeolocationProvider,
-                   nsIGeolocationProvider)
+NS_IMPL_ISUPPORTS2(GonkGPSGeolocationProvider,
+                   nsIGeolocationProvider,
+                   nsIObserver)
 #endif
 
 /* static */ GonkGPSGeolocationProvider* GonkGPSGeolocationProvider::sSingleton = nullptr;
@@ -636,15 +641,16 @@ GonkGPSGeolocationProvider::SetupAGPS()
     return;
   }
 
-  // Setup network state listener
+  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+  if (obs) {
+    obs->AddObserver(this, kNetworkConnStateChangedTopic, false);
+  }
+
   nsCOMPtr<nsIRadioInterfaceLayer> ril = do_GetService("@mozilla.org/ril;1");
   if (ril) {
     // TODO: Bug 878748 - B2G GPS: acquire correct RadioInterface instance in
     // MultiSIM configuration
     ril->GetRadioInterface(0 /* clientId */, getter_AddRefs(mRadioInterface));
-    if (mRadioInterface) {
-      mRadioInterface->RegisterDataCallCallback(this);
-    }
   }
 }
 #endif // MOZ_B2G_RIL
@@ -746,8 +752,9 @@ GonkGPSGeolocationProvider::Shutdown()
     mNetworkLocationProvider = nullptr;
   }
 #ifdef MOZ_B2G_RIL
-  if (mRadioInterface) {
-    mRadioInterface->UnregisterDataCallCallback(this);
+  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+  if (obs) {
+    obs->RemoveObserver(this, kNetworkConnStateChangedTopic);
   }
 #endif
 
@@ -774,23 +781,27 @@ GonkGPSGeolocationProvider::SetHighAccuracy(bool)
   return NS_OK;
 }
 
-#ifdef MOZ_B2G_RIL
-/** nsIRILDataCallback interface **/
-
 NS_IMETHODIMP
-GonkGPSGeolocationProvider::DataCallStateChanged(nsIRILDataCallInfo* aDataCall)
+GonkGPSGeolocationProvider::Observe(nsISupports* aSubject,
+                                    const char* aTopic,
+                                    const char16_t* aData)
 {
   MOZ_ASSERT(NS_IsMainThread());
-  MOZ_ASSERT(aDataCall);
 
-  // We call Setting Service before we get the state of supl data connection
-  // since it is possible that state of supl data connection haven't been
-  // updated and will be updated after we finished this function (code that
-  // updates the state is in another dataCallStateChanged callback).
+  if (strcmp(aTopic, kNetworkConnStateChangedTopic)) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIRilNetworkInterface> iface = do_QueryInterface(aSubject);
+  if (!iface) {
+    return NS_OK;
+  }
+
   RequestSettingValue("ril.supl.apn");
   return NS_OK;
 }
 
+#ifdef MOZ_B2G_RIL
 /** nsISettingsServiceCallback **/
 
 NS_IMETHODIMP

dom/system/gonk/GonkGPSGeolocationProvider.h

@@ -20,6 +20,7 @@
 #include <hardware/gps.h> // for GpsInterface
 #include "nsCOMPtr.h"
 #include "nsIGeolocationProvider.h"
+#include "nsIObserver.h"
 #ifdef MOZ_B2G_RIL
 #include "nsIRadioInterfaceLayer.h"
 #include "nsISettingsService.h"
@@ -34,16 +35,16 @@ class nsIThread;
 "@mozilla.org/gonk-gps-geolocation-provider;1"
 
 class GonkGPSGeolocationProvider : public nsIGeolocationProvider
+                                 , public nsIObserver
 #ifdef MOZ_B2G_RIL
-                                 , public nsIRILDataCallback
                                  , public nsISettingsServiceCallback
 #endif
 {
 public:
   NS_DECL_THREADSAFE_ISUPPORTS
   NS_DECL_NSIGEOLOCATIONPROVIDER
+  NS_DECL_NSIOBSERVER
 #ifdef MOZ_B2G_RIL
-  NS_DECL_NSIRILDATACALLBACK
   NS_DECL_NSISETTINGSSERVICECALLBACK
 #endif