fix all instances of "the the"

sdk/lib/_internal/js_runtime/lib/js_string.dart

Index: sdk/lib/_internal/js_runtime/lib/js_string.dart
diff --git a/sdk/lib/_internal/js_runtime/lib/js_string.dart b/sdk/lib/_internal/js_runtime/lib/js_string.dart
index ed8189dd3a814c093dae1ea8510945c40eb10420..e82868c7b010fc02ac469cdd4a114bade104a4db 100644
--- a/sdk/lib/_internal/js_runtime/lib/js_string.dart
+++ b/sdk/lib/_internal/js_runtime/lib/js_string.dart
@@ -246,7 +246,7 @@ class JSString extends Interceptor implements String, JSIndexable {
     return index;
   }
 
-  /// Finds the index after the the last non-whitespace character, or 0.
+  /// Finds the index after the last non-whitespace character, or 0.
   /// Start looking at position [index - 1].
   static int _skipTrailingWhitespace(String string, int index) {
     const int SPACE = 0x20;