Update all occurrences of raw strings.

runtime/vm/scanner_test.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/assert.h"
 #include "vm/os.h"
 #include "vm/scanner.h"
 #include "vm/token.h"
 #include "vm/unit_test.h"
 
@@ skipping 227 matching lines @@
       Scan("\"\\u{FFFFFF}\"");
   EXPECT_EQ(2, out_of_range_high.length());
   CheckKind(out_of_range_high, 0, Token::kERROR);
   EXPECT(out_of_range_high[0].literal->Equals("invalid code point"));
   CheckKind(out_of_range_high, 1, Token::kEOS);
 }
 
 
 void RawString() {
   // rs = @"\' \\"
-  const Scanner::GrowableTokenStream& tokens = Scan("rs = @\"\\\' \\\\\"");
+  const Scanner::GrowableTokenStream& tokens = Scan("rs = r\"\\\' \\\\\"");
 
   EXPECT_EQ(4, tokens.length());
   CheckIdent(tokens, 0, "rs");
   CheckKind(tokens, 1, Token::kASSIGN);
   CheckKind(tokens, 2, Token::kSTRING);
   CheckKind(tokens, 3, Token::kEOS);
   CheckLineNumber(tokens, 2, 1);
   const char* litchars = (tokens)[2].literal->ToCString();
   EXPECT_EQ(5, (tokens)[2].literal->Length());
 
@@ skipping 181 matching lines @@
   RawString();
   MultilineString();
   EmptyString();
   EmptyMultilineString();
   NumberLiteral();
   InvalidText();
   FindLineTest();
 }
 
 }  // namespace dart