Skip paint property update and visual rect update if no geometry change

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 3127 matching lines @@
     m_paintController = PaintController::create();
 
   forAllNonThrottledFrameViews([](FrameView& frameView) {
     frameView.lifecycle().advanceTo(DocumentLifecycle::InPrePaint);
     if (frameView.canThrottleRendering()) {
       // This frame can be throttled but not throttled, meaning we are not in an
       // AllowThrottlingScope. Now this frame may contain dirty paint flags, and
       // we need to propagate the flags into the ancestor chain so that
       // PrePaintTreeWalk can reach this frame.
       frameView.setNeedsPaintPropertyUpdate();
+      if (auto owner = frameView.frame().ownerLayoutItem())
+        owner.setMayNeedPaintInvalidation();
     }
   });
 
   if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled()) {
     SCOPED_BLINK_UMA_HISTOGRAM_TIMER("Blink.PrePaint.UpdateTime");
     PrePaintTreeWalk(geometryMapper()).walk(*this);
   }
 
   forAllNonThrottledFrameViews([](FrameView& frameView) {
     frameView.lifecycle().advanceTo(DocumentLifecycle::PrePaintClean);
@@ skipping 1805 matching lines @@
   // so they should be able to tolerate some delay in receiving replies from a
   // throttled peer.
   return m_hiddenForThrottling && m_frame->isCrossOriginSubframe();
 }
 
 void FrameView::beginLifecycleUpdates() {
   // Avoid pumping frames for the initially empty document.
   if (!frame().loader().stateMachine()->committedFirstRealDocumentLoad())
     return;
   m_lifecycleUpdatesThrottled = false;
+  if (auto owner = frame().ownerLayoutItem())
+    owner.setMayNeedPaintInvalidation();
   setupRenderThrottling();
   updateRenderThrottlingStatus(m_hiddenForThrottling, m_subtreeThrottled);
   // The compositor will "defer commits" for the main frame until we
   // explicitly request them.
   if (frame().isMainFrame())
     frame().page()->chromeClient().beginLifecycleUpdates();
 }
 
 void FrameView::setInitialViewportSize(const IntSize& viewportSize) {
   if (viewportSize == m_initialViewportSize)
@@ skipping 268 matching lines @@
 void FrameView::setAnimationHost(
     std::unique_ptr<CompositorAnimationHost> host) {
   m_animationHost = std::move(host);
 }
 
 LayoutUnit FrameView::caretWidth() const {
   return LayoutUnit(getHostWindow()->windowToViewportScalar(1));
 }
 
 }  // namespace blink