Merge pull request #1729 from jason-simmons/mixed_viewport_lock

Fix a type mismatch in IconThemeData.operator==

packages/flutter/lib/src/material/icon_theme_data.dart

@@ -12,7 +12,7 @@ class IconThemeData {
     if (other is! IconThemeData)
       return false;
     final IconThemeData typedOther = other;
-    return color == typedOther;
+    return color == typedOther.color;
   }
 
   int get hashCode => color.hashCode;