Revert of Un-DCHECK-guard ThreadRestrictionVerifier for strings.

third_party/WebKit/Source/wtf/text/StringImpl.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller ( mueller@kde.org )
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2013 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 41 matching lines @@
 
 using namespace std;
 
 namespace WTF {
 
 using namespace Unicode;
 
 // As of Jan 2017, StringImpl needs 2 * sizeof(int) + 29 bits of data, and
 // sizeof(ThreadRestrictionVerifier) is 16 bytes. Thus, in DCHECK mode the
 // class may be padded to 32 bytes.
-// TODO(meade): Revert this by 17 Mar 17.
-// This is for investigating crbug.com/694520
-// #if DCHECK_IS_ON()
+#if DCHECK_IS_ON()
 static_assert(sizeof(StringImpl) <= 8 * sizeof(int),
               "StringImpl should stay small");
-// #else
-// static_assert(sizeof(StringImpl) <= 3 * sizeof(int),
-//               "StringImpl should stay small");
-// #endif
+#else
+static_assert(sizeof(StringImpl) <= 3 * sizeof(int),
+              "StringImpl should stay small");
+#endif
 
 #ifdef STRING_STATS
 
 static Mutex& statsMutex() {
   DEFINE_STATIC_LOCAL(Mutex, mutex, ());
   return mutex;
 }
 
 static HashSet<void*>& liveStrings() {
   // Notice that we can't use HashSet<StringImpl*> because then HashSet would
@@ skipping 248 matching lines @@
     return true;
   // AtomicStrings are not safe to send between threads as ~StringImpl()
   // will try to remove them from the wrong AtomicStringTable.
   if (isAtomic())
     return false;
   if (hasOneRef())
     return true;
   return false;
 }
 
-// TODO(meade): Revert this by 17 Mar 17.
-// This is for investigating crbug.com/694520
-// #if DCHECK_IS_ON()
+#if DCHECK_IS_ON()
 std::string StringImpl::asciiForDebugging() const {
   CString ascii = String(isolatedCopy()->substring(0, 128)).ascii();
   return std::string(ascii.data(), ascii.length());
 }
-// #endif
+#endif
 
 PassRefPtr<StringImpl> StringImpl::createUninitialized(unsigned length,
                                                        LChar*& data) {
   if (!length) {
     data = 0;
     return empty;
   }
 
   // Allocate a single buffer large enough to contain the StringImpl
   // struct as well as the data which it contains. This removes one
@@ skipping 1882 matching lines @@
     } else if (localeIdMatchesLang(localeIdentifier, "lt")) {
       // TODO(rob.buis) implement upper-casing rules for lt
       // like in StringImpl::upper(locale).
     }
   }
 
   return toUpper(c);
 }
 
 }  // namespace WTF