[WIP] Move layout states into the DocumentLifecycle state machine

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 417 matching lines @@
     , m_containsValidityStyleRules(false)
     , m_updateFocusAppearanceRestoresSelection(false)
     , m_containsPlugins(false)
     , m_ignoreDestructiveWriteCount(0)
     , m_titleSetExplicitly(false)
     , m_markers(adoptPtr(new DocumentMarkerController))
     , m_updateFocusAppearanceTimer(this, &Document::updateFocusAppearanceTimerFired)
     , m_cssTarget(0)
     , m_loadEventProgress(LoadEventNotRun)
     , m_startTime(currentTime())
-    , m_overMinimumLayoutThreshold(false)
     , m_scriptRunner(ScriptRunner::create(this))
     , m_xmlVersion("1.0")
     , m_xmlStandalone(StandaloneUnspecified)
     , m_hasXMLDeclaration(0)
     , m_designMode(inherit)
     , m_hasAnnotatedRegions(false)
     , m_annotatedRegionsDirty(false)
     , m_useSecureKeyboardEntryWhenActive(false)
     , m_documentClasses(documentClasses)
     , m_isViewSource(false)
@@ skipping 1093 matching lines @@
         return 0;
     }
     return TreeWalker::create(root, whatToShow, filter);
 }
 
 bool Document::shouldCallRecalcStyleForDocument()
 {
     return needsStyleRecalc() || childNeedsStyleRecalc() || childNeedsDistributionRecalc() || !m_useElementsNeedingUpdate.isEmpty() || childNeedsStyleInvalidation();
 }
 
+bool Document::shouldScheduleStyleRecalc()
+{
+    if (!isActive())
+        return false;
+    if (hasPendingStyleRecalc())
+        return false;
+    if (inStyleRecalc())
+        return false;
+    // InPreLayout will recalc style itself. There's no reason to schedule another recalc.
+    if (m_lifecycle.state() == DocumentLifecycle::InPreLayout)
+        return false;
+    return true;
+}
+
 void Document::scheduleStyleRecalc()
 {
-    if (hasPendingStyleRecalc() || !isActive() || inStyleRecalc() || !shouldScheduleLayout())
+    if (!shouldScheduleStyleRecalc() || !shouldScheduleLayout())
         return;
 
     ASSERT(shouldCallRecalcStyleForDocument());
 
     view()->scheduleAnimation();
     m_lifecycle.rewindTo(DocumentLifecycle::StyleRecalcPending);
 
     InspectorInstrumentation::didScheduleStyleRecalculation(this);
 }
 
@@ skipping 197 matching lines @@
         if (m_styleEngine->hasResolver()) {
             // Pseudo element removal and similar may only work with these flags still set. Reset them after the style recalc.
             StyleResolver& resolver = m_styleEngine->ensureResolver();
             m_styleEngine->resetCSSFeatureFlags(resolver.ensureRuleFeatureSet());
             resolver.clearStyleSharingList();
         }
 
         ASSERT(!needsStyleRecalc());
         ASSERT(!childNeedsStyleRecalc());
         ASSERT(inStyleRecalc());
-        m_lifecycle.advanceTo(DocumentLifecycle::Clean);
+        m_lifecycle.advanceTo(DocumentLifecycle::StyleClean);
     }
 
     InspectorInstrumentation::didRecalculateStyle(cookie);
 
     // As a result of the style recalculation, the currently hovered element might have been
     // detached (for example, by setting display:none in the :hover style), schedule another mouseMove event
     // to check if any other elements ended up under the mouse pointer due to re-layout.
     if (hoverNode() && !hoverNode()->renderer() && frame())
         frame()->eventHandler().dispatchFakeMouseMoveEventSoon();
 
@@ skipping 259 matching lines @@
 
     m_renderView = new RenderView(this);
     setRenderer(m_renderView);
 
     m_renderView->setIsInWindow(true);
     m_renderView->setStyle(StyleResolver::styleForDocument(*this));
     view()->updateCompositingLayersAfterStyleChange();
 
     ContainerNode::attach(context);
 
-    m_lifecycle.advanceTo(DocumentLifecycle::Clean);
+    m_lifecycle.advanceTo(DocumentLifecycle::LayoutClean);
 }
 
 void Document::detach(const AttachContext& context)
 {
     ASSERT(isActive());
     m_lifecycle.advanceTo(DocumentLifecycle::Stopping);
 
     if (page())
         page()->documentDetached(this);
 
@@ skipping 362 matching lines @@
     }
 
     // Make sure both the initial layout and reflow happen after the onload
     // fires. This will improve onload scores, and other browsers do it.
     // If they wanna cheat, we can too. -dwh
 
     if (frame()->navigationScheduler().locationChangePending() && elapsedTime() < cLayoutScheduleThreshold) {
         // Just bail out. Before or during the onload we were shifted to another page.
         // The old i-Bench suite does this. When this happens don't bother painting or laying out.
         m_loadEventProgress = LoadEventCompleted;
-        view()->unscheduleRelayout();
         return;
     }
 
     // We used to force a synchronous display and flush here.  This really isn't
     // necessary and can in fact be actively harmful if pages are loading at a rate of > 60fps
     // (if your platform is syncing flushes and limiting them to 60fps).
-    m_overMinimumLayoutThreshold = true;
     if (!ownerElement() || (ownerElement()->renderer() && !ownerElement()->renderer()->needsLayout())) {
         updateStyleIfNeeded();
 
         // Always do a layout after loading if needed.
         if (view() && renderView() && (!renderView()->firstChild() || renderView()->needsLayout()))
             view()->layout();
     }
 
     m_loadEventProgress = LoadEventCompleted;
 
@@ skipping 125 matching lines @@
     //
     //    (a) Only schedule a layout once the stylesheets are loaded.
     //    (b) Only schedule layout once we have a body element.
 
     return (haveStylesheetsLoaded() && body())
         || (documentElement() && !documentElement()->hasTagName(htmlTag));
 }
 
 bool Document::shouldParserYieldAgressivelyBeforeScriptExecution()
 {
-    return view() && view()->layoutPending() && !minimumLayoutDelay();
-}
-
-int Document::minimumLayoutDelay()
-{
-    if (m_overMinimumLayoutThreshold)
-        return 0;
-
-    int elapsed = elapsedTime();
-    m_overMinimumLayoutThreshold = elapsed > cLayoutScheduleThreshold;
-
-    // We'll want to schedule the timer to fire at the minimum layout threshold.
-    return max(0, cLayoutScheduleThreshold - elapsed);
+    return view() && view()->layoutPending();
 }
 
 int Document::elapsedTime() const
 {
     return static_cast<int>((currentTime() - m_startTime) * 1000);
 }
 
 void Document::write(const SegmentedString& text, Document* ownerDocument)
 {
     NestingLevelIncrementer nestingLevelIncrementer(m_writeRecursionDepth);
@@ skipping 2808 matching lines @@
 void Document::defaultEventHandler(Event* event)
 {
     if (frame() && frame()->remotePlatformLayer()) {
         frame()->chromeClient().forwardInputEvent(this, event);
         return;
     }
     Node::defaultEventHandler(event);
 }
 
 } // namespace WebCore