Bug 715673 - Hande browser-lastwindow-close events. r=mfinkle

mobile/android/chrome/content/browser.js

@@ -489,8 +489,27 @@ var BrowserApp = {
   },
 
   quit: function quit() {
-      window.QueryInterface(Ci.nsIDOMChromeWindow).minimize();
-      window.close();
+    // Figure out if there's at least one other browser window around.
+    let lastBrowser = true;
+    let e = Services.wm.getEnumerator("navigator:browser");
+    while (e.hasMoreElements() && lastBrowser) {
+      let win = e.getNext();
+      if (win != window)
+        lastBrowser = false;
+    }
+
+    if (lastBrowser) {
+      // Let everyone know we are closing the last browser window
+      let closingCanceled = Cc["@mozilla.org/supports-PRBool;1"].createInstance(Ci.nsISupportsPRBool);
+      Services.obs.notifyObservers(closingCanceled, "browser-lastwindow-close-requested", null);
+      if (closingCanceled.data)
+        return;
+
+      Services.obs.notifyObservers(null, "browser-lastwindow-close-granted", null);
+    }
+
+    window.QueryInterface(Ci.nsIDOMChromeWindow).minimize();
+    window.close();
   },
 
   saveAsPDF: function saveAsPDF(aBrowser) {