[ermine] remove deprecated selectionColor usage

Change-Id: If7aab733f7902ce3e47d2a39e8e2597978f2c924
Reviewed-on: https://fuchsia-review.googlesource.com/c/experiences/+/432876
Reviewed-by: Yeonhee Lee <yhlee@google.com>
Testability-Review: Chase Latta <chaselatta@google.com>
Commit-Queue: Chase Latta <chaselatta@google.com>
diff --git a/bin/simple_browser/lib/app.dart b/bin/simple_browser/lib/app.dart
index 36d20d1..d3e2cb0 100644
--- a/bin/simple_browser/lib/app.dart
+++ b/bin/simple_browser/lib/app.dart
@@ -47,10 +47,12 @@
                   title: Strings.browser,
                   theme: ThemeData(
                     fontFamily: 'RobotoMono',
-                    textSelectionColor: _kErmineColor200,
-                    textSelectionHandleColor: _kErmineColor400,
+                    textSelectionTheme: TextSelectionThemeData(
+                      selectionColor: _kErmineColor200,
+                      cursorColor: _kErmineColor400,
+                      selectionHandleColor: _kErmineColor400,
+                    ),
                     hintColor: _kErmineColor400,
-                    cursorColor: _kErmineColor400,
                     primaryColor: _kErmineColor100,
                     canvasColor: _kErmineColor100,
                     accentColor: _kErmineColor400,
diff --git a/session_shells/ermine/shell/lib/src/utils/styles.dart b/session_shells/ermine/shell/lib/src/utils/styles.dart
index e609620..c75f855 100644
--- a/session_shells/ermine/shell/lib/src/utils/styles.dart
+++ b/session_shells/ermine/shell/lib/src/utils/styles.dart
@@ -13,7 +13,8 @@
     brightness: Brightness.dark,
     fontFamily: 'Roboto Mono',
     textTheme: TextTheme(),
-    textSelectionColor: Colors.grey[400],
+    textSelectionTheme:
+        TextSelectionThemeData(selectionColor: Colors.grey[400]),
   );
 
   /// Background color.