Store local border box property cache outside ObjectPaintProperties

third_party/WebKit/Source/core/layout/LayoutObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  *               (http://www.torchmobile.com/)
@@ skipping 67 matching lines @@
 #include "core/page/Page.h"
 #include "core/paint/ObjectPaintInvalidator.h"
 #include "core/paint/ObjectPaintProperties.h"
 #include "core/paint/PaintLayer.h"
 #include "core/style/ContentData.h"
 #include "core/style/CursorData.h"
 #include "platform/InstanceCounters.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/geometry/TransformState.h"
 #include "platform/graphics/GraphicsLayer.h"
+#include "platform/graphics/paint/PropertyTreeState.h"
 #include "platform/instrumentation/tracing/TracedValue.h"
 #include "wtf/allocator/Partitions.h"
 #include "wtf/text/StringBuilder.h"
 #include "wtf/text/WTFString.h"
 #ifndef NDEBUG
 #include <stdio.h>
 #endif
 
 namespace blink {
 
@@ skipping 3447 matching lines @@
       isBackgroundAttachmentFixedObject)
     return;
   m_bitfields.setIsBackgroundAttachmentFixedObject(
       isBackgroundAttachmentFixedObject);
   if (isBackgroundAttachmentFixedObject)
     frameView()->addBackgroundAttachmentFixedObject(this);
   else
     frameView()->removeBackgroundAttachmentFixedObject(this);
 }
 
-LayoutObject::RarePaintData::RarePaintData() : m_paintProperties(nullptr) {}
+LayoutObject::RarePaintData::RarePaintData()
+    : m_paintProperties(nullptr),
+      m_localBorderBoxProperties(nullptr),
+      m_contentsProperties(nullptr) {}

[Xianzhu, 2017/03/30 00:41:11]

Nit: omit this to use default constructor of unique_ptr?

 
 LayoutObject::RarePaintData::~RarePaintData() {}
 
 ObjectPaintProperties& LayoutObject::RarePaintData::ensurePaintProperties() {
   if (!m_paintProperties)
     m_paintProperties = ObjectPaintProperties::create();
   return *m_paintProperties.get();
 }
 
+void LayoutObject::RarePaintData::clearLocalBorderBoxProperties() {
+  m_localBorderBoxProperties = nullptr;
+
+  // The contents properties are based on the border box so we need to clear
+  // the cached value.
+  m_contentsProperties = nullptr;
+}
+
+void LayoutObject::RarePaintData::setLocalBorderBoxProperties(
+    PropertyTreeState& state) {
+  if (!m_localBorderBoxProperties)
+    m_localBorderBoxProperties = WTF::makeUnique<PropertyTreeState>(state);
+  else
+    *m_localBorderBoxProperties = state;
+
+  // The contents properties are based on the border box so we need to clear
+  // the cached value.
+  m_contentsProperties = nullptr;
+}
+
+const PropertyTreeState* LayoutObject::RarePaintData::contentsProperties()
+    const {
+  if (!m_contentsProperties) {
+    if (m_localBorderBoxProperties) {
+      m_contentsProperties = ObjectPaintProperties::contentsProperties(
+          m_localBorderBoxProperties.get(), m_paintProperties.get());
+    }
+  } else {
+#if DCHECK_IS_ON()
+    // Check that the cached contents properties are valid by checking that they
+    // do not change if recalculated.
+    DCHECK(m_localBorderBoxProperties);
+    std::unique_ptr<PropertyTreeState> oldProperties =
+        std::move(m_contentsProperties);
+    m_contentsProperties = ObjectPaintProperties::contentsProperties(
+        m_localBorderBoxProperties.get(), m_paintProperties.get());
+    DCHECK(*m_contentsProperties == *oldProperties);
+#endif
+  }
+  return m_contentsProperties.get();
+}
+
 LayoutObject::RarePaintData& LayoutObject::ensureRarePaintData() {
   if (!m_rarePaintData)
     m_rarePaintData = WTF::makeUnique<RarePaintData>();
   return *m_rarePaintData.get();
 }
 
 LayoutRect LayoutObject::debugRect() const {
   LayoutRect rect;
   LayoutBlock* block = containingBlock();
   if (block)
@@ skipping 55 matching lines @@
     const blink::LayoutObject* root = object1;
     while (root->parent())
       root = root->parent();
     root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
   } else {
     WTFLogAlways("%s", "Cannot showLayoutTree. Root is (nil)");
   }
 }
 
 #endif