Atom will auto-update on close if a newer version is on Speakeasy

The first call to terminate is canceled so that every window can be 
closed. On AtomCefClient the OnBeforeClose method is called when a
browser is finished closing. Once all windows have finished closing, AtomCefClient calls terminate again, which will terminate the 
application.

Closes #527

native/atom_application.mm

@@ -278,12 +278,21 @@
   }
 }
 
+// The first call to terminate is canceled so that every window can be closed.
+// On AtomCefClient the OnBeforeClose method is called when a browser is
+// finished closing. Once all windows have finished closing, AtomCefClient calls
+// terminate again, which will terminate the application.
 - (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender {
-  for (NSWindow *window in [self windows]) {
-    [window performClose:self];
+  if (self.windows.count > 0) {
+    for (NSWindow *window in self.windows) {
+      [window performClose:self];
+    }
+    return NSTerminateCancel;
+  }
+  else {
+    CefQuitMessageLoop();
+    return NSTerminateNow;
   }
-
-  return NSTerminateCancel;
 }
 
 # pragma mark CefAppProtocol

native/atom_cef_client.cpp

@@ -174,7 +174,7 @@ void AtomCefClient::OnBeforeClose(CefRefPtr<CefBrowser> browser) {
   m_Browser = NULL;
   numberOfOpenBrowsers--;
   if (numberOfOpenBrowsers == 0) {
-    CefQuitMessageLoop();
+    Terminate();
   }
 }
 

native/atom_cef_client.h

@@ -127,6 +127,7 @@ class AtomCefClient : public CefClient,
   void ShowSaveDialog(int replyId, CefRefPtr<CefBrowser> browser);
   CefRefPtr<CefListValue> CreateReplyDescriptor(int replyId, int callbackIndex);
   void Exit(int status);
+  void Terminate();
   void Log(const char *message);
   void Show(CefRefPtr<CefBrowser> browser);
   void ToggleFullScreen(CefRefPtr<CefBrowser> browser);

native/atom_cef_client_mac.mm

@@ -159,6 +159,10 @@ void AtomCefClient::Exit(int status) {
   exit(status);
 }
 
+void AtomCefClient::Terminate() {
+  [NSApp terminate:NSApp];
+}
+
 void AtomCefClient::Log(const char *message) {
   NSLog(@"%s", message);
 }