Rename Tab.LockIcon to Tab.SecurityState

The tab's state is concerned with whether or not the page is secure. It should
not mention the lock icon, as this is just a UI choice of how to represent the
security state.

Also renames WebViewController.onUpdatedLockIcon() to onUpdatedSecurityState().

No functional change.

Bug: 5403366
Change-Id: Id18402e84fd9b1f661c160189c7a19a9352fd25c
diff --git a/src/com/android/browser/PageDialogsHandler.java b/src/com/android/browser/PageDialogsHandler.java
index 14373cb..9c0f063 100644
--- a/src/com/android/browser/PageDialogsHandler.java
+++ b/src/com/android/browser/PageDialogsHandler.java
@@ -98,7 +98,7 @@
         mHttpAuthenticationDialog.setCancelListener(new HttpAuthenticationDialog.CancelListener() {
             public void onCancel() {
                 handler.cancel();
-                mController.onUpdatedLockIcon(tab);
+                mController.onUpdatedSecurityState(tab);
                 mHttpAuthenticationDialog = null;
             }
         });