Bug 1880783 - Remove skip_cursor_move_for_same_value_set pref r=dom-core,masayuki

Differential Revision: https://phabricator.services.mozilla.com/D207025

dom/html/TextControlState.cpp

@@ -2877,8 +2877,7 @@ bool TextControlState::SetValueWithoutTextEditor(
 
   // We can't just early-return here, because OnValueChanged below still need to
   // be called.
-  if (!mValue.Equals(aHandlingSetValue.GetSettingValue()) ||
-      !StaticPrefs::dom_input_skip_cursor_move_for_same_value_set()) {
+  if (!mValue.Equals(aHandlingSetValue.GetSettingValue())) {
     bool handleSettingValue = true;
     // If `SetValue()` call is nested, `GetSettingValue()` result will be
     // modified.  So, we need to store input event data value before

modules/libpref/init/StaticPrefList.yaml

@@ -2845,13 +2845,6 @@
   value: 8
   mirror: always
 
-# Enable not moving the cursor to end when a text input or textarea has .value
-# set to the value it already has.  By default, enabled.
-- name: dom.input.skip_cursor_move_for_same_value_set
-  type: bool
-  value: true
-  mirror: always
-
 # How often to check for CPOW timeouts (ms). CPOWs are only timed
 # out by the hang monitor.
 - name: dom.ipc.cpow.timeout