Make Position::FirstPositionInNode() to take const Node& instead of Node*

third_party/WebKit/Source/core/editing/PositionTest.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/editing/Position.h"
 
 #include "core/editing/EditingTestBase.h"
 
 namespace blink {
 
 class PositionTest : public EditingTestBase {};
 
 TEST_F(PositionTest, IsEquivalent) {
   SetBodyContent("<a id=sample>0<b>1</b>2</a>");
 
   Element* sample = GetDocument().getElementById("sample");
 
   EXPECT_TRUE(Position(sample, 0).IsEquivalent(Position(sample, 0)));
 
   EXPECT_TRUE(
-      Position(sample, 0).IsEquivalent(Position::FirstPositionInNode(sample)));
+      Position(sample, 0).IsEquivalent(Position::FirstPositionInNode(*sample)));
   EXPECT_TRUE(Position(sample, 0).IsEquivalent(
       Position::BeforeNode(*sample->firstChild())));
   EXPECT_TRUE(Position(sample, 1).IsEquivalent(
       Position::AfterNode(*sample->firstChild())));
   EXPECT_TRUE(Position(sample, 1).IsEquivalent(
       Position::BeforeNode(*sample->firstChild()->nextSibling())));
   EXPECT_TRUE(Position(sample, 2).IsEquivalent(
       Position::BeforeNode(*sample->lastChild())));
   EXPECT_TRUE(Position(sample, 3).IsEquivalent(
       Position::AfterNode(*sample->lastChild())));
@@ skipping 190 matching lines @@
   const char* shadow_content = "";
   SetBodyContent(body_content);
   ShadowRoot* shadow_root = SetShadowContent(shadow_content, "host");
   Element* host = GetDocument().getElementById("host");
 
   EXPECT_EQ(PositionInFlatTree(host, PositionAnchorType::kAfterChildren),
             ToPositionInFlatTree(Position(shadow_root, 0)));
 }
 
 }  // namespace blink