Reduce PropertyTreeState construction and copies

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

 // Copyright 2015 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/PaintPropertyTreeBuilderTest.h"
 
 #include "core/html/HTMLIFrameElement.h"
 #include "core/layout/LayoutTreeAsText.h"
 #include "core/paint/ObjectPaintProperties.h"
 #include "core/paint/PaintPropertyTreePrinter.h"
@@ skipping 59 matching lines @@
   Settings::setMockScrollbarsEnabled(false);
 }
 
 #define CHECK_VISUAL_RECT(expected, sourceLayoutObject, ancestorLayoutObject,  \
                           slopFactor)                                          \
   do {                                                                         \
     GeometryMapper geometryMapper;                                             \
     LayoutRect source((sourceLayoutObject)->localVisualRect());                \
     source.moveBy((sourceLayoutObject)->paintOffset());                        \
     bool success = false;                                                      \
-    auto contentsProperties =                                                  \
-        (ancestorLayoutObject)->paintProperties()->contentsProperties();       \
+    const auto& contentsProperties =                                           \
+        *(ancestorLayoutObject)->paintProperties()->contentsProperties();      \
     LayoutRect actual =                                                        \
         LayoutRect(geometryMapper.sourceToDestinationVisualRect(               \
             FloatRect(source), *(sourceLayoutObject)                           \
                                     ->paintProperties()                        \
                                     ->localBorderBoxProperties(),              \
             contentsProperties, success));                                     \
     ASSERT_TRUE(success);                                                      \
     actual.moveBy(-(ancestorLayoutObject)->paintOffset());                     \
     EXPECT_EQ(expected, actual)                                                \
         << "GeometryMapper: expected: " << expected.toString()                 \
@@ skipping 2251 matching lines @@
   const ObjectPaintProperties* childProperties = child->paintProperties();
 
   // No scroll translation because the document does not scroll (not enough
   // content).
   EXPECT_TRUE(!frameScrollTranslation());
   EXPECT_EQ(framePreTranslation(),
             clipProperties->localBorderBoxProperties()->transform());
   EXPECT_EQ(frameContentClip(),
             clipProperties->localBorderBoxProperties()->clip());
 
-  auto contentsProperties = clipProperties->contentsProperties();
+  const auto& contentsProperties = *clipProperties->contentsProperties();
   EXPECT_EQ(LayoutPoint(30, 20), clipper->paintOffset());
   EXPECT_EQ(framePreTranslation(), contentsProperties.transform());
   EXPECT_EQ(clipProperties->overflowClip(), contentsProperties.clip());
 
   EXPECT_EQ(framePreTranslation(),
             childProperties->localBorderBoxProperties()->transform());
   EXPECT_EQ(clipProperties->overflowClip(),
             childProperties->localBorderBoxProperties()->clip());
 
   EXPECT_NE(nullptr, childProperties->localBorderBoxProperties()->effect());
@@ skipping 16 matching lines @@
   const ObjectPaintProperties* childProperties = child->paintProperties();
 
   // No scroll translation because the document does not scroll (not enough
   // content).
   EXPECT_TRUE(!frameScrollTranslation());
   EXPECT_EQ(framePreTranslation(),
             clipProperties->localBorderBoxProperties()->transform());
   EXPECT_EQ(frameContentClip(),
             clipProperties->localBorderBoxProperties()->clip());
 
-  auto contentsProperties = clipProperties->contentsProperties();
+  const auto& contentsProperties = *clipProperties->contentsProperties();
   EXPECT_EQ(LayoutPoint(30, 20), clipper->paintOffset());
   EXPECT_EQ(framePreTranslation(), contentsProperties.transform());
   EXPECT_EQ(clipProperties->overflowClip(), contentsProperties.clip());
 
   EXPECT_EQ(framePreTranslation(),
             childProperties->localBorderBoxProperties()->transform());
   EXPECT_EQ(clipProperties->overflowClip(),
             childProperties->localBorderBoxProperties()->clip());
 
   EXPECT_NE(nullptr, childProperties->localBorderBoxProperties()->effect());
@@ skipping 20 matching lines @@
       toLayoutBoxModelObject(clipperElement->layoutObject());
   const ObjectPaintProperties* clipProperties = clipper->paintProperties();
   LayoutObject* child = document().getElementById("child")->layoutObject();
   const ObjectPaintProperties* childProperties = child->paintProperties();
 
   EXPECT_EQ(frameScrollTranslation(),
             clipProperties->localBorderBoxProperties()->transform());
   EXPECT_EQ(frameContentClip(),
             clipProperties->localBorderBoxProperties()->clip());
 
-  auto contentsProperties = clipProperties->contentsProperties();
+  const auto& contentsProperties = *clipProperties->contentsProperties();
   EXPECT_EQ(LayoutPoint(30, 20), clipper->paintOffset());
   EXPECT_EQ(clipProperties->scrollTranslation(),
             contentsProperties.transform());
   EXPECT_EQ(clipProperties->overflowClip(), contentsProperties.clip());
 
   EXPECT_EQ(clipProperties->scrollTranslation(),
             childProperties->localBorderBoxProperties()->transform());
   EXPECT_EQ(clipProperties->overflowClip(),
             childProperties->localBorderBoxProperties()->clip());
 
@@ skipping 64 matching lines @@
 
   // No scroll translation because the document does not scroll (not enough
   // content).
   EXPECT_TRUE(!frameScrollTranslation());
   EXPECT_EQ(framePreTranslation(),
             clipProperties->localBorderBoxProperties()->transform());
   // CSS clip on an element causes it to clip itself, not just descendants.
   EXPECT_EQ(clipProperties->cssClip(),
             clipProperties->localBorderBoxProperties()->clip());
 
-  auto contentsProperties = clipProperties->contentsProperties();
+  const auto& contentsProperties = *clipProperties->contentsProperties();
   EXPECT_EQ(LayoutPoint(30, 20), clipper->paintOffset());
   EXPECT_EQ(framePreTranslation(), contentsProperties.transform());
   EXPECT_EQ(clipProperties->cssClip(), contentsProperties.clip());
 
   CHECK_EXACT_VISUAL_RECT(LayoutRect(0, 0, 400, 500), child, clipper);
 }
 
 TEST_P(PaintPropertyTreeBuilderTest,
        SvgLocalToBorderBoxTransformContentsTreeState) {
   setBodyInnerHTML(
@@ skipping 14 matching lines @@
       "</svg>");
 
   LayoutObject& svgWithViewBox =
       *document().getElementById("svgWithViewBox")->layoutObject();
   const ObjectPaintProperties* svgWithViewBoxProperties =
       svgWithViewBox.paintProperties();
 
   EXPECT_EQ(framePreTranslation(),
             svgWithViewBoxProperties->localBorderBoxProperties()->transform());
 
-  auto contentsProperties = svgWithViewBoxProperties->contentsProperties();
+  const auto& contentsProperties =
+      *svgWithViewBoxProperties->contentsProperties();
   EXPECT_EQ(LayoutPoint(30, 20), svgWithViewBox.paintOffset());
   EXPECT_EQ(framePreTranslation(), contentsProperties.transform());
 }
 
 TEST_P(PaintPropertyTreeBuilderTest, OverflowHiddenScrollProperties) {
   setBodyInnerHTML(
       "<style>"
       "  body {"
       "    margin: 0px;"
       "  }"
@@ skipping 580 matching lines @@
 
   LayoutObject* target = getLayoutObjectByElementId("target");
   const auto* localBorderBoxProperties =
       target->paintProperties()->localBorderBoxProperties();
   ASSERT_TRUE(localBorderBoxProperties);
   EXPECT_EQ(LayoutPoint(66, 55), target->paintOffset());
   EXPECT_EQ(effect, localBorderBoxProperties->effect());
 }
 
 }  // namespace blink