url: patched to compile on Android.

src/core/android/SDL_android.c

@@ -2284,6 +2284,11 @@ void *SDL_AndroidGetActivity(void)
     return (*env)->CallStaticObjectMethod(env, mActivityClass, midGetContext);
 }
 
+jclass Android_GetActivityClass(void)
+{
+    return mActivityClass;
+}
+
 int SDL_GetAndroidSDKVersion(void)
 {
     static int sdk_version;