Subtree caching implementation in blink-core

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 feffce69b9fc3057ce92d0ef13c11897d32aa012..b28b8e60c4e152c3db6cbc1d0d8011fdc9e60ba1 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -2454,26 +2454,29 @@ void FrameView::updateLifecyclePhasesInternal(LifeCycleUpdateOption phases)
 
         ASSERT(lifecycle().state() >= DocumentLifecycle::CompositingClean);
 
-        if (phases == AllPhases) {
-            invalidateTreeIfNeededRecursive();
-
-            if (view->compositor()->inCompositingMode())
-                scrollingCoordinator()->updateAfterCompositingChangeIfNeeded();
+        if (phases == OnlyUpToCompositingCleanPlusScrolling)
+            return;
 
-            updateCompositedSelectionIfNeeded();
+        invalidateTreeIfNeededRecursive();
 
-            if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
-                paintForSlimmingPaintV2();
-                compositeForSlimmingPaintV2();
-            }
+        if (view->compositor()->inCompositingMode())
+            scrollingCoordinator()->updateAfterCompositingChangeIfNeeded();
 
-            if (RuntimeEnabledFeatures::frameTimingSupportEnabled())
-                updateFrameTimingRequestsIfNeeded();
+        updateCompositedSelectionIfNeeded();
 
-            ASSERT(!view->hasPendingSelection());
-            ASSERT(lifecycle().state() == DocumentLifecycle::PaintInvalidationClean
-                || (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && lifecycle().state() == DocumentLifecycle::CompositingForSlimmingPaintV2Clean));
+        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
+            paintForSlimmingPaintV2();
+            if (phases == OnlyUpToPaintForSlimmingPaintV2Clean)
+                return;
+            compositeForSlimmingPaintV2();
         }
+
+        if (RuntimeEnabledFeatures::frameTimingSupportEnabled())
+            updateFrameTimingRequestsIfNeeded();
+
+        ASSERT(!view->hasPendingSelection());
+        ASSERT(lifecycle().state() == DocumentLifecycle::PaintInvalidationClean
+            || (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && lifecycle().state() == DocumentLifecycle::CompositingForSlimmingPaintV2Clean));
     }
 }