Back out 767debcb04d8 (bug 823325) for Android test_manyWindows.html failures.

mobile/android/chrome/content/browser.js

@@ -2812,7 +2812,6 @@ Tab.prototype = {
       this.browser.docShellIsActive = true;
     } else {
       this.browser.setAttribute("type", "content-targetable");
-      this.browser.blur();
       this.browser.docShellIsActive = false;
     }
   },