Cherry-pick WebKit change 53441 to make changes to Geolocation

See http://trac.webkit.org/changeset/53441

This is required to bring Geolocation up-to-date with webkit.org to allow upstreaming of maximumAge code.

Change-Id: Ib69ddd4d1b0944c861ac6c35412936ec1209cff0
diff --git a/WebCore/ChangeLog b/WebCore/ChangeLog
index 68d2cd1..20bedf2 100644
--- a/WebCore/ChangeLog
+++ b/WebCore/ChangeLog
@@ -1,3 +1,23 @@
+2010-01-18  Steve Falkenburg  <sfalken@apple.com>
+
+        Reviewed by Sam Weinig.
+
+        <https://bugs.webkit.org/show_bug.cgi?id=33816>        
+        Crashes in Geolocation code due to refcounting, observer balance issues.
+        
+        Hold a ref to the GeoNotifier while dispatching a callback. The code was
+        copying a data member to avoid accessing a freed this ptr, but was still
+        using the this ptr.
+        
+        Geolocation::removeObserver calls are not always balanced with addObserver.
+        Instead of asserting and continuing, don't try to remove non-existant
+        observers.
+
+        * page/Geolocation.cpp:
+        (WebCore::Geolocation::GeoNotifier::timerFired): Protect notifier.
+        * page/GeolocationController.cpp:
+        (WebCore::GeolocationController::removeObserver): Change ASSERT into an if with early return.
+
 2009-12-14  Sam Weinig  <sam@webkit.org>
 
         Fix the build.
diff --git a/WebCore/page/Geolocation.cpp b/WebCore/page/Geolocation.cpp
index 231d57a..cc5cc93 100644
--- a/WebCore/page/Geolocation.cpp
+++ b/WebCore/page/Geolocation.cpp
@@ -121,15 +121,15 @@
 {
     m_timer.stop();
 
-    // Cache our pointer to the Geolocation object, as this GeoNotifier object
+    // Protect this GeoNotifier object, since it
     // could be deleted by a call to clearWatch in a callback.
-    Geolocation* geolocation = m_geolocation;
+    RefPtr<GeoNotifier> protect(this);
 
     if (m_fatalError) {
         if (m_errorCallback)
             m_errorCallback->handleEvent(m_fatalError.get());
         // This will cause this notifier to be deleted.
-        geolocation->fatalErrorOccurred(this);
+        m_geolocation->fatalErrorOccurred(this);
         return;
     }
 
@@ -138,7 +138,7 @@
         // Clear the cached position in case this is a watch request, which
         // will continue to run.
         m_cachedPosition = 0;
-        geolocation->requestReturnedCachedPosition(this);
+        m_geolocation->requestReturnedCachedPosition(this);
         return;
     }
 
@@ -146,7 +146,7 @@
         RefPtr<PositionError> error = PositionError::create(PositionError::TIMEOUT, "Timeout expired");
         m_errorCallback->handleEvent(error.get());
     }
-    geolocation->requestTimedOut(this);
+    m_geolocation->requestTimedOut(this);
 }
 
 void Geolocation::Watchers::set(int id, PassRefPtr<GeoNotifier> prpNotifier)
diff --git a/WebCore/page/GeolocationController.cpp b/WebCore/page/GeolocationController.cpp
index 44eba6e..968e854 100644
--- a/WebCore/page/GeolocationController.cpp
+++ b/WebCore/page/GeolocationController.cpp
@@ -54,7 +54,8 @@
 
 void GeolocationController::removeObserver(Geolocation* observer)
 {
-    ASSERT(m_observers.contains(observer));
+    if (!m_observers.contains(observer))
+        return;
 
     m_observers.remove(observer);
     if (m_observers.isEmpty())