Compute snap offsets (both repeat and element based)

third_party/WebKit/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 171 matching lines @@
 #include "core/loader/ImageLoader.h"
 #include "core/loader/NavigationScheduler.h"
 #include "core/loader/appcache/ApplicationCacheHost.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/EventWithHitTestResults.h"
 #include "core/page/FocusController.h"
 #include "core/page/FrameTree.h"
 #include "core/page/Page.h"
 #include "core/page/PointerLockController.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
+#include "core/page/scrolling/SnapCoordinator.h"
 #include "core/svg/SVGDocumentExtensions.h"
 #include "core/svg/SVGTitleElement.h"
 #include "core/svg/SVGUseElement.h"
 #include "core/timing/DOMWindowPerformance.h"
 #include "core/timing/Performance.h"
 #include "core/workers/SharedWorkerRepositoryClient.h"
 #include "core/xml/parser/XMLDocumentParser.h"
 #include "platform/DateComponents.h"
 #include "platform/EventDispatchForbiddenScope.h"
 #include "platform/Language.h"
@@ skipping 5081 matching lines @@
 void Document::setThreadedParsingEnabledForTesting(bool enabled)
 {
     s_threadedParsingEnabledForTesting = enabled;
 }
 
 bool Document::threadedParsingEnabledForTesting()
 {
     return s_threadedParsingEnabledForTesting;
 }
 
+SnapCoordinator* Document::snapCoordinator()
+{
+    if (RuntimeEnabledFeatures::cssScrollSnapPointsEnabled() && !m_snapCoordinator)
+        m_snapCoordinator = SnapCoordinator::create();
+
+    return m_snapCoordinator.get();
+}
+
 bool Document::hasActiveParser()
 {
     return m_activeParserCount || (m_parser && m_parser->processingData());
 }
 
 void Document::setContextFeatures(ContextFeatures& features)
 {
     m_contextFeatures = PassRefPtrWillBeRawPtr<ContextFeatures>(features);
 }
 
@@ skipping 449 matching lines @@
     visitor->trace(m_timers);
     visitor->trace(m_templateDocument);
     visitor->trace(m_templateDocumentHost);
     visitor->trace(m_visibilityObservers);
     visitor->trace(m_userActionElements);
     visitor->trace(m_svgExtensions);
     visitor->trace(m_timeline);
     visitor->trace(m_compositorPendingAnimations);
     visitor->trace(m_contextDocument);
     visitor->trace(m_canvasFontCache);
+    visitor->trace(m_snapCoordinator);
     WillBeHeapSupplementable<Document>::trace(visitor);
 #endif
     TreeScope::trace(visitor);
     ContainerNode::trace(visitor);
     ExecutionContext::trace(visitor);
     DocumentLifecycleNotifier::trace(visitor);
     SecurityContext::trace(visitor);
 }
 
 template class CORE_TEMPLATE_EXPORT WillBeHeapSupplement<Document>;
 
 } // namespace blink
 
 #ifndef NDEBUG
 using namespace blink;
 void showLiveDocumentInstances()
 {
     Document::WeakDocumentSet& set = Document::liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (Document* document : set)
         fprintf(stderr, "- Document %p URL: %s\n", document, document->url().string().utf8().data());
 }
 #endif