[web] Allow users to enable canvas text measurement (flutter#13929)

mdebbar · web-flow · commit f6a3eb9d1938 · 2019-11-21T12:37:07.000-08:00
diff --git a/lib/web_ui/lib/src/engine/text/measurement.dart b/lib/web_ui/lib/src/engine/text/measurement.dart
@@ -184,7 +184,7 @@ abstract class TextMeasurementService {
   ///
   /// This is only used for testing at the moment. Once the implementation is
   /// complete and production-ready, we'll get rid of this flag.
-  static bool enableExperimentalCanvasImplementation = false;
+  static bool enableExperimentalCanvasImplementation = const bool.fromEnvironment('FLUTTER_WEB_USE_EXPERIMENTAL_CANVAS_TEXT', defaultValue: false);
 
   /// Gets the appropriate [TextMeasurementService] instance for the given
   /// [paragraph].
