Fix build of own emoji functions

third_party/WebKit/Source/platform/text/ICUError.h

 // 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.
 
 #ifndef ICUError_h
 #define ICUError_h
 
 #include "platform/PlatformExport.h"
 #include "wtf/Allocator.h"
 #include "wtf/Assertions.h"
 #include <unicode/utypes.h>
 
 namespace blink {
 
 // ICUError provides the unified way to handle ICU errors in Blink.
 class PLATFORM_EXPORT ICUError {
   STACK_ALLOCATED();
 
  public:
   ~ICUError() { crashIfCritical(); }
 
   UErrorCode* operator&() { return &m_error; }
   operator UErrorCode() const { return m_error; }
+  operator UErrorCode&() { return m_error; }
 
   void operator=(UErrorCode error) { m_error = error; }
 
   // Crash the renderer in the appropriate way if critical failure occurred.
   void crashIfCritical();
 
  private:
   UErrorCode m_error = U_ZERO_ERROR;
 
   void handleFailure();
 };
 
 inline void ICUError::crashIfCritical() {
   if (U_FAILURE(m_error))
     handleFailure();
 }
 
 }  // namespace blink
 
 #endif  // ICUError_h