Dart SDK Spelling b, c, and d.

pkg/compiler/lib/src/js_backend/runtime_types.dart

Index: pkg/compiler/lib/src/js_backend/runtime_types.dart
diff --git a/pkg/compiler/lib/src/js_backend/runtime_types.dart b/pkg/compiler/lib/src/js_backend/runtime_types.dart
index 4c1eed13f228b8588488b11961ed28045a76d7e3..041880e50246a3583cda47eae11aecede597adbc 100644
--- a/pkg/compiler/lib/src/js_backend/runtime_types.dart
+++ b/pkg/compiler/lib/src/js_backend/runtime_types.dart
@@ -91,7 +91,7 @@ abstract class RuntimeTypesSubstitutions {
 
   Substitution getSubstitution(ClassElement cls, ClassElement other);
 
-  /// Compute the required type checkes and substitutions for the given
+  /// Compute the required type checks and substitutions for the given
   /// instantitated and checked classes.
   TypeChecks computeChecks(
       Set<ClassElement> instantiated, Set<ClassElement> checked);