Revert "The expected key is a valid identifier, which is already free of \\, <0x20, "."

src/json-parser.h

Index: src/json-parser.h
diff --git a/src/json-parser.h b/src/json-parser.h
index 9a22738e98d9ae806366d94da030a345b10fed63..4d451389174be9047fafce183fcaa18b0f687b98 100644
--- a/src/json-parser.h
+++ b/src/json-parser.h
@@ -108,8 +108,9 @@ class JsonParser BASE_EMBEDDED {
         const uint8_t* expected_chars = content.ToOneByteVector().start();
         for (int i = 0; i < length; i++) {
           uint8_t c0 = input_chars[i];
-          // The expected string has to be free of \, " and characters < 0x20.
-          if (c0 != expected_chars[i]) return false;
+          if (c0 != expected_chars[i] || c0 == '"' || c0 < 0x20 || c0 == '\\') {
+            return false;
+          }
         }
         if (input_chars[length] == '"') {
           position_ = position_ + length + 1;