Introduce String::fromUTF8Lenient() and use it for cache_name in CacheStorage API.

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

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007-2009 Torch Mobile, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 851 matching lines @@
         return emptyString16Bit();
 
     UChar* destination;
     String result = String::createUninitialized(length, destination);
 
     StringImpl::copyChars(destination, source, length);
 
     return result;
 }
 
-String String::fromUTF8(const LChar* stringStart, size_t length)
+String String::fromUTF8(const LChar* stringStart, size_t length, bool strict)
 {
     RELEASE_ASSERT(length <= std::numeric_limits<unsigned>::max());
 
     if (!stringStart)
         return String();
 
     if (!length)
         return emptyString();
 
     if (charactersAreAllASCII(stringStart, length))
         return StringImpl::create(stringStart, length);
 
     Vector<UChar, 1024> buffer(length);
     UChar* bufferStart = buffer.data();
 
     UChar* bufferCurrent = bufferStart;
     const char* stringCurrent = reinterpret_cast<const char*>(stringStart);
-    if (convertUTF8ToUTF16(&stringCurrent, reinterpret_cast<const char *>(stringStart + length), &bufferCurrent, bufferCurrent + buffer.size()) != conversionOK)
+    if (convertUTF8ToUTF16(&stringCurrent, reinterpret_cast<const char*>(stringStart + length), &bufferCurrent, bufferCurrent + buffer.size(), nullptr, strict) != conversionOK)
         return String();
 
     unsigned utf16Length = bufferCurrent - bufferStart;
     ASSERT(utf16Length < length);
     return StringImpl::create(bufferStart, utf16Length);
 }
 
 String String::fromUTF8(const LChar* string)
 {
     if (!string)
@@ skipping 337 matching lines @@
     buffer.append('\0');
     return buffer;
 }
 
 Vector<char> asciiDebug(String& string)
 {
     return asciiDebug(string.impl());
 }
 
 #endif