[WIP] Move layout states into the DocumentLifecycle state machine

Source/core/frame/FrameView.cpp

Index: Source/core/frame/FrameView.cpp
diff --git a/Source/core/frame/FrameView.cpp b/Source/core/frame/FrameView.cpp
index 6fbb16e0d01bddf93e854a636b9dbb6e7ca13be1..5ddac493d6573f9307f94c1bd9cc3f7f55f78e88 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -223,10 +223,8 @@ void FrameView::reset()
     m_contentIsOpaque = false;
     m_hasPendingLayout = false;
     m_layoutSubtreeRoot = 0;
-    m_delayedLayout = false;
     m_doFullRepaint = true;
     m_layoutSchedulingEnabled = true;
-    m_inPerformLayout = false;
     m_canRepaintDuringPerformLayout = false;
     m_doingPreLayoutStyleUpdate = false;
     m_inSynchronousPostLayout = false;
@@ -498,7 +496,6 @@ void FrameView::adjustViewSize()
     const IntRect rect = renderView->documentRect();
     const IntSize& size = rect.size();
     ScrollView::setScrollOrigin(IntPoint(-rect.x(), -rect.y()), !m_frame->document()->printing(), size == contentsSize());
-
     setContentsSize(size);
 }
 
@@ -778,6 +775,7 @@ inline void FrameView::forceLayoutParentViewIfNeeded()
 void FrameView::performPreLayoutTasks()
 {
     TRACE_EVENT0("webkit", "FrameView::performPreLayoutTasks");
+    lifecycle().advanceTo(DocumentLifecycle::InPreLayout);
 
     // Don't schedule more layouts, we're in one.
     TemporaryChange<bool> changeSchedulingEnabled(m_layoutSchedulingEnabled, false);
@@ -790,6 +788,8 @@ void FrameView::performPreLayoutTasks()
     }
 
     Document* document = m_frame->document();
+
+    // FIXME: Should we move this code to FrameView::setContentsSize?
     document->notifyResizeForViewportUnits();
 
     // Viewport-dependent media queries may cause us to need completely different style information.
@@ -812,15 +812,15 @@ void FrameView::performPreLayoutTasks()
     // the layout beats any sort of style recalc update that needs to occur.
     TemporaryChange<bool> changeDoingPreLayoutStyleUpdate(m_doingPreLayoutStyleUpdate, true);
     document->updateStyleIfNeeded();
+    lifecycle().advanceTo(DocumentLifecycle::StyleClean);

[ojan, 2014/02/06 05:11:39]

I wonder if updateStyleIfNeeded should be doing this. Not clear.

[abarth-chromium, 2014/02/06 05:31:15]

Yeah, I wondered that too.  I tried a few variations on that idea, but this
seemed simpler for the time being.  Some of the tricky cases involve calling
updateStyleIfNeeded while the document is inactive.  In those cases, we don't
need to update the style but we also don't end up in the StyleClean state.

 }
 
 void FrameView::performLayout(RenderObject* rootForThisLayout, bool inSubtreeLayout)
 {
-    ASSERT(!m_inPerformLayout);
-
     TRACE_EVENT0("webkit", "FrameView::performLayout");
 
-    TemporaryChange<bool> changeInPerformLayout(m_inPerformLayout, true);
+    ASSERT(!isInPerformLayout());
+    lifecycle().advanceTo(DocumentLifecycle::InPerformLayout);
 
     // performLayout is the actual guts of layout().
     // FIXME: The 300 other lines in layout() probably belong in other helper functions
@@ -857,6 +857,8 @@ void FrameView::performLayout(RenderObject* rootForThisLayout, bool inSubtreeLay
 
     if (inSubtreeLayout)
         rootForThisLayout->view()->popLayoutState(rootForThisLayout);
+
+    lifecycle().advanceTo(DocumentLifecycle::AfterPerformLayout);
 }
 
 void FrameView::scheduleOrPerformPostLayoutTasks()
@@ -892,10 +894,7 @@ void FrameView::layout(bool allowSubtree)
     ASSERT(m_frame->view() == this);
     ASSERT(m_frame->page());
 
-    if (m_inPerformLayout)
-        return;
-
-    if (!m_frame->document()->isActive())
+    if (isInPerformLayout() || !lifecycle().isActive())
         return;
 
     ASSERT(!partialLayout().isStopping());
@@ -910,12 +909,10 @@ void FrameView::layout(bool allowSubtree)
     TemporaryChange<bool> changeInProgrammaticScroll(m_inProgrammaticScroll, true);
 
     m_hasPendingLayout = false;
-    m_delayedLayout = false;
+    DocumentLifecycle::Scope lifecycleScope(lifecycle(), DocumentLifecycle::LayoutClean);
 
-    // we shouldn't enter layout() while painting
-    ASSERT(!isPainting());
-    if (isPainting())
-        return;
+    // We shouldn't enter layout() while painting
+    RELEASE_ASSERT(!isPainting());
 
     // Store the current maximal outline size to use when computing the old/new
     // outline rects for repainting.
@@ -946,6 +943,9 @@ void FrameView::layout(bool allowSubtree)
 
     bool isPartialLayout = partialLayout().isPartialLayout();
 
+    if (isPartialLayout)
+        lifecycleScope.setFinalState(DocumentLifecycle::StyleClean);
+
     FontCachePurgePreventer fontCachePurgePreventer;
     RenderLayer* layer;
     {
@@ -1160,6 +1160,11 @@ void FrameView::repaintTree(RenderObject* root)
     resetScrollbarDamage();
 }
 
+DocumentLifecycle& FrameView::lifecycle() const
+{
+    return m_frame->document()->lifecycle();
+}
+
 void FrameView::gatherDebugLayoutRects(RenderObject* layoutRoot)
 {
     bool isTracing;
@@ -1807,13 +1812,6 @@ void FrameView::scheduleRelayout()
         return;
     InspectorInstrumentation::didInvalidateLayout(m_frame.get());
 
-    int delay = m_frame->document()->minimumLayoutDelay();
-    if (m_hasPendingLayout && m_delayedLayout && !delay)
-        unscheduleRelayout();
-    if (m_hasPendingLayout)
-        return;
-
-    m_delayedLayout = delay != 0;
     m_hasPendingLayout = true;
     scheduleAnimation();
 }
@@ -1860,11 +1858,9 @@ void FrameView::scheduleRelayoutOfSubtree(RenderObject* relayoutRoot)
             }
         }
     } else if (m_layoutSchedulingEnabled) {
-        int delay = m_frame->document()->minimumLayoutDelay();
         m_layoutSubtreeRoot = relayoutRoot;
         ASSERT(!m_layoutSubtreeRoot->container() || !m_layoutSubtreeRoot->container()->needsLayout());
         InspectorInstrumentation::didInvalidateLayout(m_frame.get());
-        m_delayedLayout = delay != 0;
         m_hasPendingLayout = true;
         scheduleAnimation();
     }
@@ -1875,6 +1871,11 @@ bool FrameView::layoutPending() const
     return m_hasPendingLayout;
 }
 
+bool FrameView::isInPerformLayout() const
+{
+    return lifecycle().state() == DocumentLifecycle::InPerformLayout;
+}
+
 bool FrameView::needsLayout() const
 {
     // This can return true in cases where the document does not have a body yet.
@@ -1893,15 +1894,6 @@ void FrameView::setNeedsLayout()
         renderView->setNeedsLayout();
 }
 
-void FrameView::unscheduleRelayout()
-{
-    if (!m_hasPendingLayout)
-        return;
-
-    m_hasPendingLayout = false;
-    m_delayedLayout = false;
-}
-
 void FrameView::serviceScriptedAnimations(double monotonicAnimationStartTime)
 {
     for (RefPtr<Frame> frame = m_frame; frame; frame = frame->tree().traverseNext()) {
@@ -2330,7 +2322,7 @@ void FrameView::invalidateScrollbarRect(Scrollbar* scrollbar, const IntRect& rec
     IntRect dirtyRect = rect;
     dirtyRect.moveBy(scrollbar->location());
 
-    if (RuntimeEnabledFeatures::repaintAfterLayoutEnabled() && m_inPerformLayout) {
+    if (RuntimeEnabledFeatures::repaintAfterLayoutEnabled() && isInPerformLayout()) {
         if (scrollbar == verticalScrollbar()) {
             m_verticalBarDamage = dirtyRect;
             m_hasVerticalBarDamage = true;