Show AUTOFILL in the overflow menu

To be consistent with Android native view, this patch make WebView always show AUTOFILL menun in the overflow menu.

Bug: 907698
Change-Id: Ibe9e8bfd3850177339cfd969488649b44b5524d5
Reviewed-on: https://chromium-review.googlesource.com/c/1347000
Commit-Queue: Tao Bai <michaelbai@chromium.org>
Reviewed-by: Changwan Ryu <changwan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611267}

android_webview/java/src/org/chromium/android_webview/AutofillActionModeCallback.java

@@ -42,7 +42,7 @@ public class AutofillActionModeCallback implements ActionMode.Callback {
             MenuItem item = menu.add(
                     Menu.NONE, mAutofillMenuItem, Menu.CATEGORY_SECONDARY, mAutofillMenuItemTitle);
             item.setShowAsActionFlags(
-                    MenuItem.SHOW_AS_ACTION_IF_ROOM | MenuItem.SHOW_AS_ACTION_WITH_TEXT);
+                    MenuItem.SHOW_AS_ACTION_NEVER | MenuItem.SHOW_AS_ACTION_WITH_TEXT);
         }
         return true;
     }