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

third_party/WebKit/Source/modules/imagecapture/PhotoCapabilities.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 "modules/imagecapture/PhotoCapabilities.h"
 
 namespace blink {
 
 namespace {
 
 String meteringModeToString(media::mojom::blink::MeteringMode mode) {
   switch (mode) {
     case media::mojom::blink::MeteringMode::NONE:
       return "none";
     case media::mojom::blink::MeteringMode::MANUAL:
       return "manual";
     case media::mojom::blink::MeteringMode::SINGLE_SHOT:
       return "single-shot";
     case media::mojom::blink::MeteringMode::CONTINUOUS:
       return "continuous";
     default:
       NOTREACHED();
   }
-  return emptyString();
+  return emptyString;
 }
 
 }  // anonymous namespace
 
 // static
 PhotoCapabilities* PhotoCapabilities::create() {
   return new PhotoCapabilities();
 }
 
 String PhotoCapabilities::focusMode() const {
@@ skipping 16 matching lines @@
       return "off";
     case media::mojom::blink::FillLightMode::AUTO:
       return "auto";
     case media::mojom::blink::FillLightMode::FLASH:
       return "flash";
     case media::mojom::blink::FillLightMode::TORCH:
       return "torch";
     default:
       NOTREACHED();
   }
-  return emptyString();
+  return emptyString;
 }
 
 DEFINE_TRACE(PhotoCapabilities) {
   visitor->trace(m_iso);
   visitor->trace(m_imageHeight);
   visitor->trace(m_imageWidth);
   visitor->trace(m_zoom);
   visitor->trace(m_exposureCompensation);
   visitor->trace(m_colorTemperature);
   visitor->trace(m_brightness);
   visitor->trace(m_contrast);
   visitor->trace(m_saturation);
   visitor->trace(m_sharpness);
 }
 
 }  // namespace blink