Support chrome.windows extension API events for browserless Panels.

chrome/browser/ui/panels/panel_cocoa.mm

Index: chrome/browser/ui/panels/panel_cocoa.mm
diff --git a/chrome/browser/ui/panels/panel_cocoa.mm b/chrome/browser/ui/panels/panel_cocoa.mm
index eb38a92fddef069d2515d290db2145553342408d..4fbdb0224fd220e47ca7df64716a8d12f2b9ce6f 100644
--- a/chrome/browser/ui/panels/panel_cocoa.mm
+++ b/chrome/browser/ui/panels/panel_cocoa.mm
@@ -51,6 +51,12 @@ bool PanelCocoa::isClosed() {
 void PanelCocoa::ShowPanel() {
   ShowPanelInactive();
   ActivatePanel();
+
+  // |-makeKeyAndOrderFront:| won't send |-windowDidBecomeKey:| until we
+  // return to the runloop. This causes extension tests that wait for the
+  // active status change notification to fail, so we send an active status
+  // notification here.
+  panel_->OnActiveStateChanged(true);
 }
 
 void PanelCocoa::ShowPanelInactive() {