delete unused lib/src/engine/canvaskit/viewport_metrics.dart (#38474)

* delete unused lib/src/engine/canvaskit/viewport_metrics.dart

* fix licenses

ci/licenses_golden/licenses_flutter

diff --git a/ci/licenses_golden/licenses_flutter b/ci/licenses_golden/licenses_flutter
index eece0b9..78a37a3 100644
--- a/ci/licenses_golden/licenses_flutter
+++ b/ci/licenses_golden/licenses_flutter
@@ -1893,7 +1893,6 @@
 ORIGIN: ../../../flutter/lib/web_ui/lib/src/engine/canvaskit/text.dart + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/lib/web_ui/lib/src/engine/canvaskit/util.dart + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/lib/web_ui/lib/src/engine/canvaskit/vertices.dart + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/lib/web_ui/lib/src/engine/canvaskit/viewport_metrics.dart + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/lib/web_ui/lib/src/engine/clipboard.dart + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/lib/web_ui/lib/src/engine/color_filter.dart + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/lib/web_ui/lib/src/engine/configuration.dart + ../../../flutter/LICENSE
@@ -4344,7 +4343,6 @@
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/canvaskit/text.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/canvaskit/util.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/canvaskit/vertices.dart
-FILE: ../../../flutter/lib/web_ui/lib/src/engine/canvaskit/viewport_metrics.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/clipboard.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/color_filter.dart
 FILE: ../../../flutter/lib/web_ui/lib/src/engine/configuration.dart

lib/web_ui/lib/src/engine/canvaskit/viewport_metrics.dart

diff --git a/lib/web_ui/lib/src/engine/canvaskit/viewport_metrics.dart b/lib/web_ui/lib/src/engine/canvaskit/viewport_metrics.dart
deleted file mode 100644
index 255ab30..0000000
--- a/lib/web_ui/lib/src/engine/canvaskit/viewport_metrics.dart
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright 2013 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-class ViewportMetrics {
-  const ViewportMetrics(
-    this.devicePixelRatio,
-    this.physicalWidth,
-    this.physicalHeight,
-  );
-
-  final double devicePixelRatio;
-  final double physicalWidth;
-  final double physicalHeight;
-}