Backed out 2 changesets (bug 1728167, bug 1728580) for win build bustages on a CLOSED TREE

Backed out changeset d28a7b6edac6 (bug 1728580)
Backed out changeset fc05d1c0d88a (bug 1728167)

Author: AndreeaPavel

toolkit/mozapps/update/updater/launchchild_osx.mm

@@ -450,59 +450,3 @@ void SetGroupOwnershipAndPermissions(const char* aAppBundle) {
     }
   }
 }
-
-#if !defined(MAC_OS_X_VERSION_10_13) || MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_13
-@interface NSTask (NSTask10_13)
-@property(copy) NSURL* executableURL NS_AVAILABLE_MAC(10_13);
-@property(copy) NSArray<NSString*>* arguments;
-- (BOOL)launchAndReturnError:(NSError**)error NS_AVAILABLE_MAC(10_13);
-@end
-#endif
-
-/**
- * Helper to launch macOS tasks via NSTask.
- */
-static void LaunchTask(NSString* aPath, NSArray* aArguments) {
-  if (@available(macOS 10.13, *)) {
-    NSTask* task = [[NSTask alloc] init];
-    [task setExecutableURL:[NSURL fileURLWithPath:aPath]];
-    if (aArguments) {
-      [task setArguments:aArguments];
-    }
-    [task launchAndReturnError:nil];
-    [task release];
-  } else {
-    NSArray* arguments = aArguments;
-    if (!arguments) {
-      arguments = @[];
-    }
-    [NSTask launchedTaskWithLaunchPath:aPath arguments:arguments];
-  }
-}
-
-static void RegisterAppWithLaunchServices(NSString* aBundlePath) {
-  NSArray* arguments = @[ @"-f", aBundlePath ];
-  LaunchTask(@"/System/Library/Frameworks/CoreServices.framework/Frameworks/"
-             @"LaunchServices.framework/Support/lsregister",
-             arguments);
-}
-
-static void StripQuarantineBit(NSString* aBundlePath) {
-  NSArray* arguments = @[ @"-d", @"com.apple.quarantine", aBundlePath ];
-  LaunchTask(@"/usr/bin/xattr", arguments);
-}
-
-bool PerformInstallationFromDMG(int argc, char** argv) {
-  MacAutoreleasePool pool;
-  if (argc < 4) {
-    return false;
-  }
-  NSString* bundlePath = [NSString stringWithUTF8String:argv[2]];
-  NSString* destPath = [NSString stringWithUTF8String:argv[3]];
-  if ([[NSFileManager defaultManager] copyItemAtPath:bundlePath toPath:destPath error:nil]) {
-    RegisterAppWithLaunchServices(destPath);
-    StripQuarantineBit(destPath);
-    return true;
-  }
-  return false;
-}