Fixes the bug around misbehavior with empty homepage setting

  Bug: 2911567
  Setting the homepage to "" resulted in odd behavior. This changes
  it so that entering "" fails with an invalid URL error (now a toast
  instead of a dialog). The "Use Current" button was replaced with a
  "Set to..." button that allows the user to specify whether they want
  to set the homepage to the current page, a blank page, or the default page.

Change-Id: I2d0cac158f89ace6ecab6165a3768419ba3252d4
diff --git a/src/com/android/browser/BrowserSettings.java b/src/com/android/browser/BrowserSettings.java
index 3b8aaa4..20b6003 100644
--- a/src/com/android/browser/BrowserSettings.java
+++ b/src/com/android/browser/BrowserSettings.java
@@ -678,7 +678,7 @@
         appCacheMaxSize = webStorageSizeManager.getAppCacheMaxSize();
     }
 
-    private String getFactoryResetHomeUrl(Context context) {
+    /*package*/ static String getFactoryResetHomeUrl(Context context) {
         String url = context.getResources().getString(R.string.homepage_base);
         if (url.indexOf("{CID}") != -1) {
             url = url.replace("{CID}",