Bug 619670 - onLowMemory may not work on android. Need to forward event. r=dougt/blassey. a=blocking-fennec

--HG--
extra : rebase_source : eca6be2a6b82f2e2d2dd71870b036878afbbafa8

widget/src/android/AndroidJNI.cpp

@@ -92,9 +92,11 @@ Java_org_mozilla_gecko_GeckoAppShell_setSurfaceView(JNIEnv *jenv, jclass, jobjec
 NS_EXPORT void JNICALL
 Java_org_mozilla_gecko_GeckoAppShell_onLowMemory(JNIEnv *jenv, jclass jc)
 {
-    nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
-    if (os)
-        os->NotifyObservers(nsnull, "memory-pressure", NS_LITERAL_STRING("low-memory").get());
+    if (nsAppShell::gAppShell) {
+        nsAppShell::gAppShell->NotifyObservers(nsnull,
+                                               "memory-pressure",
+                                               NS_LITERAL_STRING("low-memory").get());
+    }
 }
 
 NS_EXPORT void JNICALL

widget/src/android/nsAppShell.cpp

@@ -425,6 +425,40 @@ nsAppShell::RemoveObserver(const nsAString &aObserverKey)
     mObserversHash.Remove(aObserverKey);
 }
 
+// NotifyObservers support.  NotifyObservers only works on main thread.
+
+class NotifyObserversCaller : public nsRunnable {
+public:
+    NotifyObserversCaller(nsISupports *aSupports,
+                          const char *aTopic, const PRUnichar *aData) :
+         mSupports(aSupports), mTopic(aTopic), mData(aData) {
+    }
+
+    NS_IMETHOD Run() {
+        nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+        if (os)
+            os->NotifyObservers(mSupports, mTopic.get(), mData.get());
+
+        return NS_OK;
+    }
+
+private:
+    nsCOMPtr<nsISupports> mSupports;
+    nsCString mTopic;
+    nsString mData;
+};
+
+void
+nsAppShell::NotifyObservers(nsISupports *aSupports,
+                            const char *aTopic,
+                            const PRUnichar *aData)
+{
+    // This isn't main thread, so post this to main thread
+    nsCOMPtr<nsIRunnable> caller =
+        new NotifyObserversCaller(aSupports, aTopic, aData);
+    NS_DispatchToMainThread(caller);
+}
+
 // Used by IPC code
 namespace mozilla {
 

widget/src/android/nsAppShell.h

@@ -74,6 +74,7 @@ public:
     nsresult AddObserver(const nsAString &aObserverKey, nsIObserver *aObserver);
     void CallObserver(const nsAString &aObserverKey, const nsAString &aTopic, const nsAString &aData);
     void RemoveObserver(const nsAString &aObserverKey);
+    void NotifyObservers(nsISupports *aSupports, const char *aTopic, const PRUnichar *aData);
 
 protected:
     virtual void ScheduleNativeEventCallback();