[reland] Bring up BrowserActionInteractiveTest on Mac.

chrome/browser/ui/cocoa/extensions/browser_action_test_util_mac.mm

Index: chrome/browser/ui/cocoa/extensions/browser_action_test_util_mac.mm
diff --git a/chrome/browser/ui/cocoa/extensions/browser_action_test_util_mac.mm b/chrome/browser/ui/cocoa/extensions/browser_action_test_util_mac.mm
index 2c97e95fe4cb50742c4f4242b696443afe43b8dc..ca7928264f5f2389c7e5a9ca6792af6d355b68af 100644
--- a/chrome/browser/ui/cocoa/extensions/browser_action_test_util_mac.mm
+++ b/chrome/browser/ui/cocoa/extensions/browser_action_test_util_mac.mm
@@ -26,6 +26,7 @@
 #include "chrome/browser/ui/toolbar/toolbar_action_view_controller.h"
 #include "chrome/browser/ui/toolbar/toolbar_actions_bar.h"
 #include "chrome/common/chrome_constants.h"
+#import "ui/base/test/windowed_nsnotification_observer.h"
 #include "ui/base/theme_provider.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
@@ -158,6 +159,23 @@ gfx::NativeView BrowserActionTestUtil::GetPopupNativeView() {
   return popup_owner ? popup_owner->GetPopupNativeView() : nil;
 }
 
+bool BrowserActionTestUtil::WaitForPopup() {
+  NSWindow* window = [GetPopupNativeView() window];
+  if (!window)
+    return false;
+
+  if ([window isKeyWindow])
+    return true;
+
+  base::scoped_nsobject<WindowedNSNotificationObserver> waiter(
+      [[WindowedNSNotificationObserver alloc]
+          initForNotification:NSWindowDidBecomeKeyNotification
+                       object:window]);
+
+  BOOL notification_observed = [waiter wait];
+  return notification_observed && [window isKeyWindow];
+}
+
 bool BrowserActionTestUtil::HasPopup() {
   return GetPopupNativeView() != nil;
 }