Simplify ScanJsonString.

src/scanner.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 439 matching lines @@
 
   next_.location.end_pos = source_pos();
   next_.token = token;
 }
 
 
 Token::Value JsonScanner::ScanJsonString() {
   ASSERT_EQ('"', c0_);
   Advance();
   LiteralScope literal(this);
-  while (c0_ != '"' && c0_ > 0) {
+  while (c0_ != '"') {
     // Check for control character (0x00-0x1f) or unterminated string (<0).
     if (c0_ < 0x20) return Token::ILLEGAL;
     if (c0_ != '\\') {
       AddLiteralCharAdvance();
     } else {
       Advance();
       switch (c0_) {
         case '"':
         case '\\':
         case '/':
@@ skipping 26 matching lines @@
           }
           AddLiteralChar(value);
           break;
         }
         default:
           return Token::ILLEGAL;
       }
       Advance();
     }
   }
-  if (c0_ != '"') {
-    return Token::ILLEGAL;
-  }
   literal.Complete();
   Advance();
   return Token::STRING;
 }
 
 
 Token::Value JsonScanner::ScanJsonNumber() {
   LiteralScope literal(this);
   if (c0_ == '-') AddLiteralCharAdvance();
   if (c0_ == '0') {
@@ skipping 36 matching lines @@
     text++;
   }
   if (ScannerConstants::kIsIdentifierPart.get(c0_)) return Token::ILLEGAL;
   literal.Complete();
   return token;
 }
 
 
 
 } }  // namespace v8::internal