fix: enable autofill popups on mac (#16308)

* feat: enable autofill popups on mac

* fix: make popup positioning better

* fix: don't try to show popup when widget is closing or not visible

* fix: unify conditions

* refactor: use PopupViewCommon from chrome directly

* lint: mark constructor explicit

* fix: use a patch instead of dummy functions to make things compile on Windows

* chore: address review suggestions

* Update atom/browser/ui/cocoa/views_delegate_mac.mm

Co-Authored-By: brenca <benecene@gmail.com>

patches/common/chromium/autofill_size_calculation.patch

@@ -0,0 +1,31 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Heilig Benedek <benecene@gmail.com>
+Date: Wed, 30 Jan 2019 17:04:33 +0100
+Subject: don't call into chrome internals for autofill popup size calculations
+
+The default GetWindowBounds calls into chrome internal functions to
+find out the size of the window - this can be overridden but even
+then some methods call into the original. Let's just return an empty
+gfx::Rect and do the actual job in the subclass.
+
+diff --git a/chrome/browser/ui/autofill/popup_view_common.cc b/chrome/browser/ui/autofill/popup_view_common.cc
+index 004e9cb86bee7c10f6a68cdf6ceb60bf39627e1d..c6da9a8f5c14615bf22192f540b6fd95fa1ccb0e 100644
+--- a/chrome/browser/ui/autofill/popup_view_common.cc
++++ b/chrome/browser/ui/autofill/popup_view_common.cc
+@@ -176,14 +176,14 @@ gfx::Rect PopupViewCommon::GetWindowBounds(gfx::NativeView container_view) {
+       views::Widget::GetTopLevelWidgetForNativeView(container_view);
+   if (widget)
+     return widget->GetWindowBoundsInScreen();
+-
++#if 0
+   // If the widget is null, try to get these bounds from a browser window. This
+   // is common on Mac when the window is drawn using Cocoa.
+   gfx::NativeWindow window = platform_util::GetTopLevel(container_view);
+   Browser* browser = chrome::FindBrowserWithWindow(window);
+   if (browser)
+     return browser->window()->GetBounds();
+-
++#endif
+   // If the browser is null, simply return an empty rect. The most common reason
+   // to end up here is that the NativeView has been destroyed externally, which
+   // can happen at any time. This happens fairly commonly on Windows (e.g., at