Unreviewed, reverting 264051@main.

https://bugs.webkit.org/show_bug.cgi?id=259381

Caused a release assertion failure in RenderBlock::endAndCommitUpdateScrollInfoAfterLayoutTransaction

Reverted changeset:

"Deploy LayoutDisallowedScope in LayoutPhase::InRenderTreeLayout"
https://bugs.webkit.org/show_bug.cgi?id=256661
https://commits.webkit.org/264051@main

Canonical link: https://commits.webkit.org/266193@main

Source/WebCore/page/LocalFrameViewLayoutContext.cpp

@@ -192,7 +192,7 @@ void LocalFrameViewLayoutContext::layout()
 void LocalFrameViewLayoutContext::performLayout()
 {
     RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(!frame().document()->inRenderTreeUpdate());
-    RELEASE_ASSERT(LayoutDisallowedScope::isLayoutAllowed());
+    ASSERT(LayoutDisallowedScope::isLayoutAllowed());
     ASSERT(!view().isPainting());
     ASSERT(frame().view() == &view());
     ASSERT(frame().document());
@@ -246,7 +246,6 @@ void LocalFrameViewLayoutContext::performLayout()
     {
         SetForScope layoutPhase(m_layoutPhase, LayoutPhase::InRenderTreeLayout);
         ScriptDisallowedScope::InMainThread scriptDisallowedScope;
-        LayoutDisallowedScope layoutDisallowedScope(LayoutDisallowedScope::Reason::ReentrancyAvoidance);
         SubtreeLayoutStateMaintainer subtreeLayoutStateMaintainer(subtreeLayoutRoot());
         RenderView::RepaintRegionAccumulator repaintRegionAccumulator(renderView());
 #ifndef NDEBUG

Source/WebCore/rendering/LayoutDisallowedScope.cpp

@@ -28,6 +28,10 @@
 
 namespace WebCore {
 
-unsigned LayoutDisallowedScope::s_currentScopeCount = 0;
+#if ASSERT_ENABLED
+
+LayoutDisallowedScope* LayoutDisallowedScope::s_currentAssertion = nullptr;
+
+#endif
 
 }

Source/WebCore/rendering/LayoutDisallowedScope.h

@@ -25,42 +25,33 @@
 
 #pragma once
 
-#include "RuntimeApplicationChecks.h"
-#include <wtf/Compiler.h>
-
 namespace WebCore {
 
 class LayoutDisallowedScope {
 public:
-    enum class Reason : bool { PerformanceOptimization, ReentrancyAvoidance };
-
-    LayoutDisallowedScope(Reason) { ++s_currentScopeCount; }
-    ~LayoutDisallowedScope() { --s_currentScopeCount; }
+    enum class Reason { PerformanceOptimization, ReentrancyAvoidance };
 
-    static bool isLayoutAllowed() { return LIKELY(!s_currentScopeCount) || UNLIKELY(!isInWebProcess()); }
+#if !ASSERT_ENABLED
+    LayoutDisallowedScope(Reason) { }
+    static bool isLayoutAllowed() { return true; }
+#else // ASSERT_ENABLED
+    LayoutDisallowedScope(Reason)
+        : m_previousAssertion(s_currentAssertion)
+    {
+        s_currentAssertion = this;
+    }
 
-    class AllowedScope {
-    public:
-        AllowedScope();
-        ~AllowedScope();
+    ~LayoutDisallowedScope()
+    {
+        s_currentAssertion = m_previousAssertion;
+    }
 
-    private:
-        unsigned m_originalCount;
-    };
+    static bool isLayoutAllowed() { return !s_currentAssertion; }
 
 private:
-    static unsigned s_currentScopeCount;
+    LayoutDisallowedScope* m_previousAssertion;
+    static LayoutDisallowedScope* s_currentAssertion;
+#endif // ASSERT_ENABLED
 };
 
-ALWAYS_INLINE LayoutDisallowedScope::AllowedScope::AllowedScope()
-    : m_originalCount { s_currentScopeCount }
-{
-    s_currentScopeCount = 0;
-}
-
-ALWAYS_INLINE LayoutDisallowedScope::AllowedScope::~AllowedScope()
-{
-    s_currentScopeCount = m_originalCount;
-}
-
 }

Source/WebCore/svg/graphics/SVGImage.cpp

@@ -39,7 +39,6 @@
 #include "ImageObserver.h"
 #include "IntRect.h"
 #include "JSDOMWindowBase.h"
-#include "LayoutDisallowedScope.h"
 #include "LegacyRenderSVGRoot.h"
 #include "LocalDOMWindow.h"
 #include "LocalFrame.h"
@@ -191,8 +190,6 @@ ImageDrawResult SVGImage::drawForContainer(GraphicsContext& context, const Float
     if (!m_page)
         return ImageDrawResult::DidNothing;
 
-    LayoutDisallowedScope::AllowedScope layoutAllowedScope; // Allow layout in the SVG document for this image.
-
     ImageObserver* observer = imageObserver();
     ASSERT(observer);
 
@@ -315,7 +312,6 @@ ImageDrawResult SVGImage::draw(GraphicsContext& context, const FloatRect& dstRec
 
     {
         ScriptDisallowedScope::DisableAssertionsInScope disabledScope;
-        LayoutDisallowedScope::AllowedScope layoutAllowedScope;
         if (view->needsLayout())
             view->layoutContext().layout();
     }