Fix obvious copy and paste fail.

Bug: 1131842
Change-Id: I0612adf1075e417bcb43cd24b69b19b96be6b7c5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2429785
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Peter Boström <pbos@chromium.org>
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810433}

ui/views/controls/textfield/textfield.cc

@@ -2509,8 +2509,8 @@ int Textfield::CharsToDips(int width_in_chars) const {
   // effects like find boxes on different tabs being 1 DIP different width.
   const int cursor_width =
       (!GetReadOnly() && GetRenderText()->cursor_enabled()) ? 1 : 0;
-  return GetFontList().GetExpectedTextWidth(default_width_in_chars_) +
-         cursor_width + GetInsets().width();
+  return GetFontList().GetExpectedTextWidth(width_in_chars) + cursor_width +
+         GetInsets().width();
 }
 
 bool Textfield::ShouldBlinkCursor() const {