Replace WTF::emptyString{16Bit}() with a static global

third_party/WebKit/Source/wtf/text/StringViewTest.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 "wtf/text/StringView.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "wtf/text/AtomicString.h"
 #include "wtf/text/StringImpl.h"
 #include "wtf/text/WTFString.h"
@@ skipping 348 matching lines @@
   EXPECT_FALSE(StringView(String(kChars)).isEmpty());
   EXPECT_TRUE(StringView(String(kChars), 5).isEmpty());
   EXPECT_TRUE(StringView(String(kChars), 4, 0).isEmpty());
   EXPECT_TRUE(StringView().isEmpty());
   EXPECT_TRUE(StringView("").isEmpty());
   EXPECT_TRUE(StringView(reinterpret_cast<const UChar*>(u"")).isEmpty());
   EXPECT_FALSE(StringView(kChars16).isEmpty());
 }
 
 TEST(StringViewTest, ToString) {
-  EXPECT_EQ(emptyString().impl(), StringView("").toString().impl());
+  EXPECT_EQ(emptyString.impl(), StringView("").toString().impl());
   EXPECT_EQ(nullAtom.impl(), StringView().toString().impl());
   // NOTE: All the construction tests also check toString().
 }
 
 TEST(StringViewTest, ToAtomicString) {
   EXPECT_EQ(nullAtom.impl(), StringView().toAtomicString());
   EXPECT_EQ(emptyAtom.impl(), StringView("").toAtomicString());
   EXPECT_EQ(AtomicString("12"), StringView(kChars8, 2).toAtomicString());
   // AtomicString will convert to 8bit if possible when creating the string.
   EXPECT_EQ(AtomicString("12").impl(),
@@ skipping 69 matching lines @@
   EXPECT_FALSE(equalIgnoringASCIICase(StringView("link"), "INKL"));
   EXPECT_FALSE(
       equalIgnoringASCIICase(StringView("link"), "link different length"));
   EXPECT_FALSE(
       equalIgnoringASCIICase(StringView("link different length"), "link"));
 
   EXPECT_TRUE(equalIgnoringASCIICase(StringView(""), ""));
 }
 
 }  // namespace WTF