add a flag for screenshot availbility

Author: nturgut

lib/web_ui/dev/test_runner.dart

@@ -371,6 +371,15 @@ class TestCommand extends Command<bool> with ArgUtils {
       isFirefoxIntegrationTestAvailable ||
       isSafariIntegrationTestAvailable;
 
+  bool get isScreenhotTestsAvailable =>
+      isIntegrationTestsAvailable || isUnitTestsScreenshotsAvailable;
+
+  // For unit tests screenshot tests and smoke tests only run on:
+  // "Chrome/iOS" for LUCI/local.
+  bool get isUnitTestsScreenshotsAvailable =>
+      ((isChrome && isLuci && io.Platform.isLinux) ||
+          ((isChrome || isSafariIOS) && !isLuci));
+
   /// Use system flutter instead of cloning the repository.
   ///
   /// Read the flag help for more details. Uses PATH to locate flutter.
@@ -397,12 +406,7 @@ class TestCommand extends Command<bool> with ArgUtils {
       'test',
     ));
 
-    // Screenshot tests and smoke tests only run on: "Chrome/iOS Safari locally"
-    // or "Chrome on a Linux bot". We can remove the Linux bot restriction
-    // after solving the git issue faced on macOS and Windows bots:
-    // TODO: https://github.com/flutter/flutter/issues/63710
-    if ((isChrome && isLuci && io.Platform.isLinux) ||
-        ((isChrome || isSafariIOS) && !isLuci)) {
+    if (isUnitTestsScreenshotsAvailable) {
       // Separate screenshot tests from unit-tests. Screenshot tests must run
       // one at a time. Otherwise, they will end up screenshotting each other.
       // This is not an issue for unit-tests.