Advance document lifecycle to CompositingClean prior to hit testing

Source/core/paint/DeprecatedPaintLayer.cpp

Index: Source/core/paint/DeprecatedPaintLayer.cpp
diff --git a/Source/core/paint/DeprecatedPaintLayer.cpp b/Source/core/paint/DeprecatedPaintLayer.cpp
index 3cf4a7d1e25a955f3196bd01fe519c62f73a8d07..1ee0afaad18572564a90cd7fb1d9ac3705722173 100644
--- a/Source/core/paint/DeprecatedPaintLayer.cpp
+++ b/Source/core/paint/DeprecatedPaintLayer.cpp
@@ -1667,6 +1667,8 @@ bool DeprecatedPaintLayer::hitTest(const HitTestRequest& request, const HitTestL
     if (request.ignoreClipping())
         hitTestArea.unite(LayoutRect(layoutObject()->view()->documentRect()));
 
+    // Make sure advance document lifecycle to CompositingClean prior to hit testing.
+    compositor()->updateIfNeededRecursive();
     DeprecatedPaintLayer* insideLayer = hitTestLayer(this, 0, result, hitTestArea, hitTestLocation, false);
     if (!insideLayer) {
         // We didn't hit any layer. If we are the root layer and the mouse is -- or just was -- down,
@@ -1792,6 +1794,8 @@ DeprecatedPaintLayer* DeprecatedPaintLayer::hitTestLayer(DeprecatedPaintLayer* r
     const LayoutRect& hitTestRect, const HitTestLocation& hitTestLocation, bool appliedTransform,
     const HitTestingTransformState* transformState, double* zOffset)
 {
+    ASSERT(layoutObject()->document().lifecycle().state() >= DocumentLifecycle::CompositingClean);
+
     if (!isSelfPaintingLayer() && !hasSelfPaintingLayerDescendant())
         return 0;