Follow API changes.

Change-Id: I1003044245db558c0c2ccfabd06fb7a9b9c94403
diff --git a/src/com/android/browser/BrowserPreferencesPage.java b/src/com/android/browser/BrowserPreferencesPage.java
index 2b42951..dae838f 100644
--- a/src/com/android/browser/BrowserPreferencesPage.java
+++ b/src/com/android/browser/BrowserPreferencesPage.java
@@ -70,7 +70,7 @@
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
             case android.R.id.home:
-                if (getFragmentManager().countBackStackEntries() > 0) {
+                if (getFragmentManager().getBackStackEntryCount() > 0) {
                     getFragmentManager().popBackStack();
                 } else {
                     finish();