--- a/dom/src/geolocation/nsGeolocation.cpp
+++ b/dom/src/geolocation/nsGeolocation.cpp
@@ -72,17 +72,17 @@ class nsGeolocationRequest
                        const GeoPositionCallback& aCallback,
                        const GeoPositionErrorCallback& aErrorCallback,
                        PositionOptions* aOptions,
                        bool aWatchPositionRequest = false,
                        int32_t aWatchId = 0);
   void Shutdown();
 
   void SendLocation(nsIDOMGeoPosition* location);
-  bool WantsHighAccuracy() {return mOptions && mOptions->mEnableHighAccuracy;}
+  bool WantsHighAccuracy() {return !mShutdown && mOptions && mOptions->mEnableHighAccuracy;}
   void SetTimeoutTimer();
   nsIPrincipal* GetPrincipal();
 
   ~nsGeolocationRequest();
 
   virtual bool Recv__delete__(const bool& allow) MOZ_OVERRIDE;
   virtual void IPDLRelease() MOZ_OVERRIDE { Release(); }
 
@@ -457,17 +457,17 @@ nsGeolocationRequest::Allow()
   // if the user has specified a maximumAge, return a cached value.
 
   uint32_t maximumAge = 0;
   if (mOptions) {
     if (mOptions->mMaximumAge > 0) {
       maximumAge = mOptions->mMaximumAge;
     }
   }
-  gs->SetHigherAccuracy(mOptions && mOptions->mEnableHighAccuracy);
+  gs->UpdateAccuracy(WantsHighAccuracy());
 
   bool canUseCache = lastPosition && maximumAge > 0 &&
     (PRTime(PR_Now() / PR_USEC_PER_MSEC) - maximumAge <=
     PRTime(cachedPositionTime));
 
   if (canUseCache) {
     // okay, we can return a cached position
     // getCurrentPosition requests serviced by the cache
@@ -597,22 +597,22 @@ nsGeolocationRequest::Shutdown()
   MOZ_ASSERT(!mShutdown, "request shutdown twice");
   mShutdown = true;
 
   if (mTimeoutTimer) {
     mTimeoutTimer->Cancel();
     mTimeoutTimer = nullptr;
   }
 
-  // This should happen last, to ensure that this request isn't taken into consideration
-  // when deciding whether existing requests still require high accuracy.
+  // If there are no other high accuracy requests, the geolocation service will
+  // notify the provider to switch to the default accuracy.
   if (mOptions && mOptions->mEnableHighAccuracy) {
     nsRefPtr<nsGeolocationService> gs = nsGeolocationService::GetGeolocationService();
     if (gs) {
-      gs->SetHigherAccuracy(false);
+      gs->UpdateAccuracy();
     }
   }
 }
 
 bool nsGeolocationRequest::Recv__delete__(const bool& allow)
 {
   if (allow) {
     (void) Allow();
@@ -915,19 +915,19 @@ nsGeolocationService::HighAccuracyReques
     if (mGeolocators[i]->HighAccuracyRequested()) {
       return true;
     }
   }
   return false;
 }
 
 void
-nsGeolocationService::SetHigherAccuracy(bool aEnable)
+nsGeolocationService::UpdateAccuracy(bool aForceHigh)
 {
-  bool highRequired = aEnable || HighAccuracyRequested();
+  bool highRequired = aForceHigh || HighAccuracyRequested();
 
   if (XRE_GetProcessType() == GeckoProcessType_Content) {
     ContentChild* cpc = ContentChild::GetSingleton();
     cpc->SendSetGeolocationHigherAccuracy(highRequired);
     return;
   }
 
   if (!mHigherAccuracy && highRequired) {
@@ -1075,16 +1075,17 @@ void
 Geolocation::Shutdown()
 {
   // Release all callbacks
   mPendingCallbacks.Clear();
   mWatchingCallbacks.Clear();
 
   if (mService) {
     mService->RemoveLocator(this);
+    mService->UpdateAccuracy();
   }
 
   mService = nullptr;
   mPrincipal = nullptr;
 }
 
 nsIDOMWindow*
 Geolocation::GetParentObject() const {

--- a/dom/src/geolocation/nsGeolocation.h
+++ b/dom/src/geolocation/nsGeolocation.h
@@ -80,18 +80,18 @@ public:
   nsresult StartDevice(nsIPrincipal* aPrincipal);
 
   // Stop the started geolocation device (gps, nmea, etc.)
   void     StopDevice();
 
   // create, or reinitalize the callback timer
   void     SetDisconnectTimer();
 
-  // request higher accuracy, if possible
-  void     SetHigherAccuracy(bool aEnable);
+  // Update the accuracy and notify the provider if changed
+  void     UpdateAccuracy(bool aForceHigh = false);
   bool     HighAccuracyRequested();
 
 private:
 
   ~nsGeolocationService();
 
   // Disconnect timer.  When this timer expires, it clears all pending callbacks
   // and closes down the provider, unless we are watching a point, and in that

--- a/dom/system/NetworkGeolocationProvider.js
+++ b/dom/system/NetworkGeolocationProvider.js
@@ -68,16 +68,19 @@ function WifiGeoPositionProvider() {
   try {
     gUseScanning = Services.prefs.getBoolPref("geo.wifi.scan");
   } catch (e) {}
 
   this.wifiService = null;
   this.timer = null;
   this.hasSeenWiFi = false;
   this.started = false;
+  // this is only used when logging is enabled, to debug interactions with the
+  // geolocation service
+  this.highAccuracy = false;
 }
 
 WifiGeoPositionProvider.prototype = {
   classID:          Components.ID("{77DA64D3-7458-4920-9491-86CC9914F904}"),
   QueryInterface:   XPCOMUtils.generateQI([Ci.nsIGeolocationProvider,
                                            Ci.nsIWifiListener,
                                            Ci.nsITimerCallback]),
   startup:  function() {
@@ -127,20 +130,22 @@ WifiGeoPositionProvider.prototype = {
       this.timer.cancel();
       this.timer = null;
     }
 
     this.started = false;
   },
 
   setHighAccuracy: function(enable) {
+    this.highAccuracy = enable;
+    LOG("setting highAccuracy to " + (this.highAccuracy?"TRUE":"FALSE"));
   },
 
   onChange: function(accessPoints) {
-    LOG("onChange called");
+    LOG("onChange called, highAccuracy = " + (this.highAccuracy?"TRUE":"FALSE"));
     this.hasSeenWiFi = true;
 
     let url = Services.urlFormatter.formatURLPref("geo.wifi.uri");
 
     function isPublic(ap) {
         let mask = "_nomap"
         let result = ap.ssid.indexOf(mask, ap.ssid.length - mask.length) == -1;
         if (result != -1) {

new file mode 100644
--- /dev/null
+++ b/dom/tests/unit/test_geolocation_reset_accuracy.js
@@ -0,0 +1,104 @@
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+const providerCID = Components.ID("{14aa4b81-e266-45cb-88f8-89595dece114}");
+const providerContract = "@mozilla.org/geolocation/provider;1";
+
+const categoryName = "geolocation-provider";
+
+var provider = {
+  QueryInterface: function eventsink_qi(iid) {
+    if (iid.equals(Components.interfaces.nsISupports) ||
+        iid.equals(Components.interfaces.nsIFactory) ||
+        iid.equals(Components.interfaces.nsIGeolocationProvider))
+      return this;
+    throw Components.results.NS_ERROR_NO_INTERFACE;
+  },
+  createInstance: function eventsink_ci(outer, iid) {
+    if (outer)
+      throw Components.results.NS_ERROR_NO_AGGREGATION;
+    return this.QueryInterface(iid);
+  },
+  lockFactory: function eventsink_lockf(lock) {
+    throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
+  },
+  startup: function() {
+  },
+  watch: function() {
+  },
+  shutdown: function() {
+  },
+  setHighAccuracy: function(enable) {
+    this._isHigh = enable;
+    if (enable) {
+      this._seenHigh = true;
+    }
+  },
+  _isHigh: false,
+  _seenHigh: false
+};
+
+let runningInParent = true;
+try {
+  runningInParent = Components.classes["@mozilla.org/xre/runtime;1"].
+                    getService(Components.interfaces.nsIXULRuntime).processType
+                    == Components.interfaces.nsIXULRuntime.PROCESS_TYPE_DEFAULT;
+}
+catch (e) { }
+
+function successCallback()
+{
+  do_check_true(false);
+  do_test_finished();
+}
+
+function errorCallback()
+{
+  do_check_true(false);
+  do_test_finished();
+}
+
+function run_test()
+{
+  if (runningInParent) {
+    // XPCShell does not get a profile by default. The geolocation service
+    // depends on the settings service which uses IndexedDB and IndexedDB
+    // needs a place where it can store databases.
+    do_get_profile();
+
+    Components.manager.nsIComponentRegistrar.registerFactory(providerCID,
+      "Unit test geo provider", providerContract, provider);
+    var catMan = Components.classes["@mozilla.org/categorymanager;1"]
+                           .getService(Components.interfaces.nsICategoryManager);
+    catMan.nsICategoryManager.addCategoryEntry(categoryName, "unit test",
+                                               providerContract, false, true);
+
+    var prefs = Cc["@mozilla.org/preferences-service;1"].getService(Ci.nsIPrefBranch);
+    prefs.setBoolPref("geo.testing.ignore_ipc_principal", true);
+    prefs.setBoolPref("geo.wifi.scan", false);
+  }
+
+  let geolocation = Cc["@mozilla.org/geolocation;1"].createInstance(Ci.nsISupports);
+
+  do_test_pending();
+
+  let watchID1 = geolocation.watchPosition(successCallback, errorCallback);
+  let watchID2 = geolocation.watchPosition(successCallback, errorCallback,
+                                           {enableHighAccuracy: true});
+
+  do_timeout(1000, function() {
+    geolocation.clearWatch(watchID2);
+    do_timeout(1000, check_results);
+  });
+}
+
+function check_results()
+{
+  if (runningInParent) {
+    // check the provider was set to high accuracy during the test
+    do_check_true(provider._seenHigh);
+    // check the provider is not currently set to high accuracy
+    do_check_false(provider._isHigh);
+  }
+  do_test_finished();
+}

new file mode 100644
--- /dev/null
+++ b/dom/tests/unit/test_geolocation_reset_accuracy_wrap.js
@@ -0,0 +1,70 @@
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+const providerCID = Components.ID("{14aa4b81-e266-45cb-88f8-89595dece114}");
+const providerContract = "@mozilla.org/geolocation/provider;1";
+
+const categoryName = "geolocation-provider";
+
+var provider = {
+  QueryInterface: function eventsink_qi(iid) {
+    if (iid.equals(Components.interfaces.nsISupports) ||
+        iid.equals(Components.interfaces.nsIFactory) ||
+        iid.equals(Components.interfaces.nsIGeolocationProvider))
+      return this;
+    throw Components.results.NS_ERROR_NO_INTERFACE;
+  },
+  createInstance: function eventsink_ci(outer, iid) {
+    if (outer)
+      throw Components.results.NS_ERROR_NO_AGGREGATION;
+    return this.QueryInterface(iid);
+  },
+  lockFactory: function eventsink_lockf(lock) {
+    throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
+  },
+  startup: function() {
+  },
+  watch: function() {
+  },
+  shutdown: function() {
+  },
+  setHighAccuracy: function(enable) {
+    this._isHigh = enable;
+    if (enable) {
+      this._seenHigh = true;
+    }
+  },
+  _isHigh: false,
+  _seenHigh: false
+};
+
+function run_test()
+{
+  // XPCShell does not get a profile by default. The geolocation service
+  // depends on the settings service which uses IndexedDB and IndexedDB
+  // needs a place where it can store databases.
+  do_get_profile();
+
+  Components.manager.nsIComponentRegistrar.registerFactory(providerCID,
+    "Unit test geo provider", providerContract, provider);
+  var catMan = Components.classes["@mozilla.org/categorymanager;1"]
+                         .getService(Components.interfaces.nsICategoryManager);
+  catMan.nsICategoryManager.addCategoryEntry(categoryName, "unit test",
+                                             providerContract, false, true);
+
+  var prefs = Cc["@mozilla.org/preferences-service;1"].getService(Ci.nsIPrefBranch);
+  prefs.setBoolPref("geo.testing.ignore_ipc_principal", true);
+  prefs.setBoolPref("geo.wifi.scan", false);
+
+  run_test_in_child("test_geolocation_reset_accuracy.js", check_results);
+}
+
+function check_results()
+{
+  // check the provider was set to high accuracy during the test
+  do_check_true(provider._seenHigh);
+  // check the provider is not currently set to high accuracy
+  do_check_false(provider._isHigh);
+
+  do_test_finished();
+}

--- a/dom/tests/unit/xpcshell.ini
+++ b/dom/tests/unit/xpcshell.ini
@@ -7,8 +7,13 @@ tail =
 [test_geolocation_provider.js]
 # Bug 684962: test hangs consistently on Android
 skip-if = os == "android"
 [test_geolocation_timeout.js]
 # Bug 919946: test hangs consistently on Android
 skip-if = os == "android"
 [test_geolocation_timeout_wrap.js]
 skip-if = os == "mac" || os == "android"
+[test_geolocation_reset_accuracy.js]
+# Bug 919946: test hangs consistently on Android
+skip-if = os == "android"
+[test_geolocation_reset_accuracy_wrap.js]
+skip-if = os == "mac" || os == "android"