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

third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/ObjectPaintInvalidator.h"
 
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/api/LayoutPartItem.h"
 #include "core/layout/compositing/CompositedLayerMapping.h"
+#include "core/paint/FindPaintOffsetAndVisualRectNeedingUpdate.h"
 #include "core/paint/PaintInvalidator.h"
 #include "core/paint/PaintLayer.h"
 #include "platform/HostWindow.h"
 #include "platform/graphics/GraphicsLayer.h"
 
 namespace blink {
 
 static bool gDisablePaintInvalidationStateAsserts = false;
 
 typedef HashMap<const LayoutObject*, LayoutRect> SelectionVisualRectMap;
@@ skipping 550 matching lines @@
 
   if (m_context.oldVisualRect != m_object.visualRect())
     return PaintInvalidationBoundsChange;
 
   return PaintInvalidationNone;
 }
 
 DISABLE_CFI_PERF
 void ObjectPaintInvalidatorWithContext::invalidateSelectionIfNeeded(
     PaintInvalidationReason reason) {
-  // Update selection rect when we are doing full invalidation (in case that the
-  // object is moved, composite status changed, etc.) or
-  // shouldInvalidationSelection is set (in case that the selection itself
+  // Update selection rect when we are doing full invalidation with geometry
+  // change (in case that the object is moved, composite status changed, etc.)
+  // or shouldInvalidationSelection is set (in case that the selection itself
   // changed).
   bool fullInvalidation = isImmediateFullPaintInvalidationReason(reason);
   if (!fullInvalidation && !m_object.shouldInvalidateSelection())
     return;
 
   DCHECK(m_object.hasSelectionVisualRect() ==
          selectionVisualRectMap().contains(&m_object));
   LayoutRect oldSelectionRect;
   if (m_object.hasSelectionVisualRect())
     oldSelectionRect = selectionVisualRectMap().at(&m_object);
-  LayoutRect newSelectionRect = m_object.localSelectionRect();
-  m_context.mapLocalRectToVisualRectInBacking(m_object, newSelectionRect);
+
+  LayoutRect newSelectionRect;
+#if DCHECK_IS_ON()
+  FindVisualRectNeedingUpdateScope finder(m_object, m_context, oldSelectionRect,
+                                          newSelectionRect);
+#endif
+  if (m_context.needsVisualRectUpdate(m_object)) {
+    newSelectionRect = m_object.localSelectionRect();
+    m_context.mapLocalRectToVisualRectInBacking(m_object, newSelectionRect);
+  } else {
+    newSelectionRect = oldSelectionRect;
+  }
 
   setSelectionVisualRect(m_object, newSelectionRect);
 
   if (!fullInvalidation) {
     fullyInvalidatePaint(PaintInvalidationSelection, oldSelectionRect,
                          newSelectionRect);
     m_context.paintingLayer->setNeedsRepaint();
     m_object.invalidateDisplayItemClients(PaintInvalidationSelection);
   }
 }
@@ skipping 29 matching lines @@
         reason = PaintInvalidationSVGResourceChange;
         break;
       }
       return PaintInvalidationNone;
     case PaintInvalidationDelayedFull:
       return PaintInvalidationDelayedFull;
     default:
       DCHECK(isImmediateFullPaintInvalidationReason(reason));
       // This allows descendants to know the computed reason if it's different
       // from the original reason before paint invalidation.
-      m_object.getMutableForPainting().setShouldDoFullPaintInvalidation(reason);
+      m_object.getMutableForPainting()
+          .setShouldDoFullPaintInvalidationWithoutGeometryChange(reason);
       fullyInvalidatePaint(reason, m_context.oldVisualRect,
                            m_object.visualRect());
   }
 
   m_context.paintingLayer->setNeedsRepaint();
   m_object.invalidateDisplayItemClients(reason);
   return reason;
 }
 
 DisablePaintInvalidationStateAsserts::DisablePaintInvalidationStateAsserts()
     : m_disabler(&gDisablePaintInvalidationStateAsserts, true) {}
 
 }  // namespace blink