Update third_party/base/compiler_specific.h.

Import Chromium's base/compiler_specific.h from r537069.

Now that FALLTHROUGH is available via compiler_specific.h, remove
FX_FALLTHROUGH.

Change-Id: I8b9631a4f007673e10e0c26951dfd61e9dcada30
Reviewed-on: https://pdfium-review.googlesource.com/32639
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

3 files changed, 8 insertions, 28 deletions

diff --git a/core/fxcrt/css/cfx_csssyntaxparser.cpp b/core/fxcrt/css/cfx_csssyntaxparser.cpp
index 97586dc59f..844337c1ca 100644
--- a/core/fxcrt/css/cfx_csssyntaxparser.cpp
+++ b/core/fxcrt/css/cfx_csssyntaxparser.cpp
@@ -12,7 +12,7 @@
 #include "core/fxcrt/css/cfx_cssdeclaration.h"
 #include "core/fxcrt/fx_codepage.h"
 #include "core/fxcrt/fx_extension.h"
-#include "core/fxcrt/fx_fallthrough.h"
+#include "third_party/base/compiler_specific.h"
 #include "third_party/base/logging.h"
 
 namespace {
@@ -75,7 +75,7 @@ CFX_CSSSyntaxStatus CFX_CSSSyntaxParser::DoSyntaxParse() {
                 SwitchMode(CFX_CSSSyntaxMode::Comment);
                 break;
               }
-              FX_FALLTHROUGH;
+              FALLTHROUGH;
             default:
               if (wch <= ' ') {
                 m_TextPlane.MoveNext();
@@ -112,7 +112,7 @@ CFX_CSSSyntaxStatus CFX_CSSSyntaxParser::DoSyntaxParse() {
                   return CFX_CSSSyntaxStatus::Selector;
                 break;
               }
-              FX_FALLTHROUGH;
+              FALLTHROUGH;
             default:
               AppendChar(wch);
               break;
@@ -137,7 +137,7 @@ CFX_CSSSyntaxStatus CFX_CSSSyntaxParser::DoSyntaxParse() {
                   return CFX_CSSSyntaxStatus::PropertyName;
                 break;
               }
-              FX_FALLTHROUGH;
+              FALLTHROUGH;
             default:
               AppendChar(wch);
               break;
@@ -147,7 +147,7 @@ CFX_CSSSyntaxStatus CFX_CSSSyntaxParser::DoSyntaxParse() {
           switch (wch) {
             case ';':
               m_TextPlane.MoveNext();
-              FX_FALLTHROUGH;
+              FALLTHROUGH;
             case '}':
               SwitchMode(CFX_CSSSyntaxMode::PropertyName);
               return CFX_CSSSyntaxStatus::PropertyValue;
@@ -157,7 +157,7 @@ CFX_CSSSyntaxStatus CFX_CSSSyntaxParser::DoSyntaxParse() {
                   return CFX_CSSSyntaxStatus::PropertyValue;
                 break;
               }
-              FX_FALLTHROUGH;
+              FALLTHROUGH;
             default:
               AppendChar(wch);
               break;
diff --git a/core/fxcrt/fx_extension.cpp b/core/fxcrt/fx_extension.cpp
index a27e0279c6..e27c78d7bf 100644
--- a/core/fxcrt/fx_extension.cpp
+++ b/core/fxcrt/fx_extension.cpp
@@ -10,7 +10,7 @@
 #include <cwctype>
 #include <limits>
 
-#include "core/fxcrt/fx_fallthrough.h"
+#include "third_party/base/compiler_specific.h"
 
 float FXSYS_wcstof(const wchar_t* pwsStr, int32_t iLength, int32_t* pUsedLen) {
   ASSERT(pwsStr);
@@ -25,7 +25,7 @@ float FXSYS_wcstof(const wchar_t* pwsStr, int32_t iLength, int32_t* pUsedLen) {
   switch (pwsStr[iUsedLen]) {
     case '-':
       bNegtive = true;
-      FX_FALLTHROUGH;
+      FALLTHROUGH;
     case '+':
       iUsedLen++;
       break;
diff --git a/core/fxcrt/fx_fallthrough.h b/core/fxcrt/fx_fallthrough.h
deleted file mode 100644
index 5587ee2295..0000000000
--- a/core/fxcrt/fx_fallthrough.h
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright 2018 PDFium 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 CORE_FXCRT_FX_FALLTHROUGH_H_
-#define CORE_FXCRT_FX_FALLTHROUGH_H_
-
-// When clang suggests inserting [[clang::fallthrough]], it first checks if
-// it knows of a macro expanding to it, and if so suggests inserting the
-// macro.  This means that this macro must be used only in code internal
-// to PDFium, so that PDFium's user code doesn't end up getting suggestions
-// for FX_FALLTHROUGH instead of the user-specific fallthrough macro.
-// So do not include this header in any of PDFium's public headers.
-#if defined(__clang__)
-#define FX_FALLTHROUGH [[clang::fallthrough]]
-#else
-#define FX_FALLTHROUGH
-#endif
-
-#endif  // CORE_FXCRT_FX_FALLTHROUGH_H_