platform apps: Disables history.pushState/replaceState in platform_app.js.

chrome/renderer/content_settings_observer.cc

Index: chrome/renderer/content_settings_observer.cc
diff --git a/chrome/renderer/content_settings_observer.cc b/chrome/renderer/content_settings_observer.cc
index 9fb675ea8109a64270d31b6db12564fc7c5b1f82..f1787b3e856926c671944ee1a776976e5f915124 100644
--- a/chrome/renderer/content_settings_observer.cc
+++ b/chrome/renderer/content_settings_observer.cc
@@ -454,10 +454,6 @@ bool ContentSettingsObserver::allowMutationEvents(bool default_value) {
   return IsPlatformApp() ? false : default_value;
 }
 
-bool ContentSettingsObserver::allowPushState() {
-  return !IsPlatformApp();
-}
-
 static void SendInsecureContentSignal(int signal) {
   UMA_HISTOGRAM_ENUMERATION("SSL.InsecureContent", signal,
                             INSECURE_CONTENT_NUM_EVENTS);