[LayoutNG] Convert physical fragments to being RefCounted.

third_party/WebKit/Source/web/tests/NGInlineLayoutTest.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/layout/ng/layout_ng_block_flow.h"
 #include "core/layout/ng/ng_constraint_space_builder.h"
 #include "core/layout/ng/ng_inline_layout_algorithm.h"
 #include "core/layout/ng/ng_inline_node.h"
 #include "platform/testing/RuntimeEnabledFeaturesTestHelpers.h"
 #include "platform/testing/UnitTestHelpers.h"
@@ skipping 30 matching lines @@
 
   compositor().beginFrame();
   ASSERT_FALSE(compositor().needsBeginFrame());
 
   Element* target = document().getElementById("target");
   LayoutNGBlockFlow* blockFlow = toLayoutNGBlockFlow(target->layoutObject());
   NGConstraintSpace* constraintSpace = constraintSpaceForElement(blockFlow);
 
   NGInlineNode* inlineBox =
       new NGInlineNode(blockFlow->firstChild(), blockFlow->mutableStyle());
-  NGPhysicalFragment* fragment =
+  RefPtr<NGPhysicalFragment> fragment =
       NGInlineLayoutAlgorithm(blockFlow, blockFlow->style(), inlineBox,
                               constraintSpace)
           .Layout();
   EXPECT_TRUE(fragment);
 
   String expectedText("Hello World!");
   EXPECT_EQ(expectedText, inlineBox->Text(0, 12));
 }
 
 TEST_F(NGInlineLayoutTest, BlockWithTextAndAtomicInline) {
   RuntimeEnabledFeatures::setLayoutNGEnabled(true);
   RuntimeEnabledFeatures::setLayoutNGInlineEnabled(true);
 
   SimRequest mainResource("https://example.com/", "text/html");
   loadURL("https://example.com/");
   mainResource.complete("<div id=\"target\">Hello <img>.</div>");
 
   compositor().beginFrame();
   ASSERT_FALSE(compositor().needsBeginFrame());
 
   Element* target = document().getElementById("target");
   LayoutNGBlockFlow* blockFlow = toLayoutNGBlockFlow(target->layoutObject());
   NGConstraintSpace* constraintSpace = constraintSpaceForElement(blockFlow);
 
   NGInlineNode* inlineBox =
       new NGInlineNode(blockFlow->firstChild(), blockFlow->mutableStyle());
-  NGPhysicalFragment* fragment =
+  RefPtr<NGPhysicalFragment> fragment =
       NGInlineLayoutAlgorithm(blockFlow, blockFlow->style(), inlineBox,
                               constraintSpace)
           .Layout();
   EXPECT_TRUE(fragment);
 
   String expectedText("Hello ");
   expectedText.append(objectReplacementCharacter);
   expectedText.append(".");
   EXPECT_EQ(expectedText, inlineBox->Text(0, 8));
+
+  // Delete the line box tree to avoid leaks in the test.
+  blockFlow->deleteLineBoxTree();
 }
 
 }  // namespace blink