document.lastModified should consider user's local time zone

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 177 matching lines @@
 #include "platform/network/ContentSecurityPolicyParsers.h"
 #include "platform/network/HTTPParsers.h"
 #include "platform/scroll/ScrollbarTheme.h"
 #include "platform/text/PlatformLocale.h"
 #include "platform/text/SegmentedString.h"
 #include "platform/weborigin/OriginAccessEntry.h"
 #include "platform/weborigin/SchemeRegistry.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "public/platform/Platform.h"
 #include "wtf/CurrentTime.h"
+#include "wtf/DateMath.h"
 #include "wtf/HashFunctions.h"
 #include "wtf/MainThread.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/TemporaryChange.h"
 #include "wtf/text/StringBuffer.h"
 #include "wtf/text/TextEncodingRegistry.h"
 
 using namespace WTF;
 using namespace Unicode;
 
@@ skipping 3854 matching lines @@
     if (result == OriginAccessEntry::MatchesOriginButIsPublicSuffix) {
         exceptionState.throwSecurityError("'" + newDomain + "' is a top-level domain.");
         return;
     }
 
     securityOrigin()->setDomainFromDOM(newDomain);
     if (m_frame)
         m_frame->script().updateSecurityOrigin(securityOrigin());
 }
 
+static double convertToLocalTime(double ms)

[tkent, 2014/07/18 14:16:56]

We have this calculation at multiple places.
https://code.google.com/p/chromium/codesearch#search/&q=utcOffset%5Cs%5C%2B%5...

We should consolidate them.

[kangil_, 2014/07/21 02:34:42]

Done.

+{
+    double utcOffset = calculateUTCOffset();
+    double dstOffset = calculateDSTOffset(ms, utcOffset);
+    return (ms + utcOffset + dstOffset);
+}
+
 // http://www.whatwg.org/specs/web-apps/current-work/#dom-document-lastmodified
 String Document::lastModified() const
 {
     DateComponents date;
     bool foundDate = false;
     if (m_frame) {
         if (DocumentLoader* documentLoader = loader()) {
             const AtomicString& httpLastModified = documentLoader->response().httpHeaderField("Last-Modified");
             if (!httpLastModified.isEmpty()) {
-                date.setMillisecondsSinceEpochForDateTime(parseDate(httpLastModified));
+                date.setMillisecondsSinceEpochForDateTime(convertToLocalTime(parseDate(httpLastModified)));
                 foundDate = true;
             }
         }
     }
     // FIXME: If this document came from the file system, the HTML5
     // specificiation tells us to read the last modification date from the file
     // system.
     if (!foundDate)
-        date.setMillisecondsSinceEpochForDateTime(currentTimeMS());
+        date.setMillisecondsSinceEpochForDateTime(convertToLocalTime(currentTimeMS()));
     return String::format("%02d/%02d/%04d %02d:%02d:%02d", date.month() + 1, date.monthDay(), date.fullYear(), date.hour(), date.minute(), date.second());
 }
 
 const KURL& Document::firstPartyForCookies() const
 {
     return topDocument().url();
 }
 
 static bool isValidNameNonASCII(const LChar* characters, unsigned length)
 {
@@ skipping 1786 matching lines @@
 using namespace WebCore;
 void showLiveDocumentInstances()
 {
     WeakDocumentSet& set = liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (WeakDocumentSet::const_iterator it = set.begin(); it != set.end(); ++it) {
         fprintf(stderr, "- Document %p URL: %s\n", *it, (*it)->url().string().utf8().data());
     }
 }
 #endif