Use FX_SAFE_FILESIZE and FX_SAFE_UINT32 in more places.

Easier to write than pdfium::base::CheckedNumeric<T>.

Change-Id: Ie699526214c723f32f5c72d809fa074a8a230e5d
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/65731
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

core/fpdfapi/edit/cpdf_creator.cpp

diff --git a/core/fpdfapi/edit/cpdf_creator.cpp b/core/fpdfapi/edit/cpdf_creator.cpp
index 44eb089..65ddc45 100644
--- a/core/fpdfapi/edit/cpdf_creator.cpp
+++ b/core/fpdfapi/edit/cpdf_creator.cpp
@@ -23,6 +23,7 @@
 #include "core/fxcrt/fx_extension.h"
 #include "core/fxcrt/fx_memory_wrappers.h"
 #include "core/fxcrt/fx_random.h"
+#include "core/fxcrt/fx_safe_types.h"
 #include "third_party/base/ptr_util.h"
 #include "third_party/base/stl_util.h"
 
@@ -93,7 +94,7 @@
     buffer += buf_size;
   }
 
-  pdfium::base::CheckedNumeric<FX_FILESIZE> safe_offset = offset_;
+  FX_SAFE_FILESIZE safe_offset = offset_;
   safe_offset += size;
   if (!safe_offset.IsValid())
     return false;

core/fpdfapi/font/cpdf_cmapparser.cpp

diff --git a/core/fpdfapi/font/cpdf_cmapparser.cpp b/core/fpdfapi/font/cpdf_cmapparser.cpp
index 7407a42..d1fe51c 100644
--- a/core/fpdfapi/font/cpdf_cmapparser.cpp
+++ b/core/fpdfapi/font/cpdf_cmapparser.cpp
@@ -13,6 +13,7 @@
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
 #include "core/fpdfapi/parser/cpdf_simple_parser.h"
 #include "core/fxcrt/fx_extension.h"
+#include "core/fxcrt/fx_safe_types.h"
 #include "core/fxge/fx_freetype.h"
 #include "third_party/base/logging.h"
 
@@ -143,7 +144,7 @@
   if (word.IsEmpty())
     return 0;
 
-  pdfium::base::CheckedNumeric<uint32_t> num = 0;
+  FX_SAFE_UINT32 num = 0;
   if (word[0] == '<') {
     for (size_t i = 1; i < word.GetLength() && std::isxdigit(word[i]); ++i) {
       num = num * 16 + FXSYS_HexCharToInt(word[i]);

core/fpdfapi/page/cpdf_shadingpattern.cpp

diff --git a/core/fpdfapi/page/cpdf_shadingpattern.cpp b/core/fpdfapi/page/cpdf_shadingpattern.cpp
index 86f5106..69696ac 100644
--- a/core/fpdfapi/page/cpdf_shadingpattern.cpp
+++ b/core/fpdfapi/page/cpdf_shadingpattern.cpp
@@ -15,6 +15,7 @@
 #include "core/fpdfapi/parser/cpdf_document.h"
 #include "core/fpdfapi/parser/cpdf_object.h"
 #include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fxcrt/fx_safe_types.h"
 
 namespace {
 
@@ -151,7 +152,7 @@
   if (m_pFunctions.size() != nExpectedNumFunctions)
     return false;
 
-  pdfium::base::CheckedNumeric<uint32_t> nTotalOutputs = 0;
+  FX_SAFE_UINT32 nTotalOutputs = 0;
   for (const auto& function : m_pFunctions) {
     if (!function)
       return false;

core/fxcodec/gif/cfx_lzwdecompressor.cpp

diff --git a/core/fxcodec/gif/cfx_lzwdecompressor.cpp b/core/fxcodec/gif/cfx_lzwdecompressor.cpp
index 14e34f5..12e0d89 100644
--- a/core/fxcodec/gif/cfx_lzwdecompressor.cpp
+++ b/core/fxcodec/gif/cfx_lzwdecompressor.cpp
@@ -11,6 +11,7 @@
 #include <memory>
 #include <utility>
 
+#include "core/fxcrt/fx_safe_types.h"
 #include "third_party/base/numerics/safe_math.h"
 
 std::unique_ptr<CFX_LZWDecompressor> CFX_LZWDecompressor::Create(
@@ -73,7 +74,7 @@
       if (bits_left_ > 31)
         return CFX_GifDecodeStatus::Error;
 
-      pdfium::base::CheckedNumeric<uint32_t> safe_code = *next_in_++;
+      FX_SAFE_UINT32 safe_code = *next_in_++;
       safe_code <<= bits_left_;
       safe_code |= code_store_;
       if (!safe_code.IsValid())

core/fxcrt/cfx_seekablestreamproxy.cpp

diff --git a/core/fxcrt/cfx_seekablestreamproxy.cpp b/core/fxcrt/cfx_seekablestreamproxy.cpp
index 3b65c14..67b304f 100644
--- a/core/fxcrt/cfx_seekablestreamproxy.cpp
+++ b/core/fxcrt/cfx_seekablestreamproxy.cpp
@@ -20,6 +20,7 @@
 #include "core/fxcrt/fx_codepage.h"
 #include "core/fxcrt/fx_extension.h"
 #include "core/fxcrt/fx_memory_wrappers.h"
+#include "core/fxcrt/fx_safe_types.h"
 #include "third_party/base/stl_util.h"
 
 namespace {
@@ -163,7 +164,7 @@
       m_iPosition = iOffset;
       break;
     case From::Current: {
-      pdfium::base::CheckedNumeric<FX_FILESIZE> new_pos = m_iPosition;
+      FX_SAFE_FILESIZE new_pos = m_iPosition;
       new_pos += iOffset;
       m_iPosition =
           new_pos.ValueOrDefault(std::numeric_limits<FX_FILESIZE>::max());
@@ -191,7 +192,7 @@
   if (!m_pStream->ReadBlockAtOffset(pBuffer, m_iPosition, iBufferSize))
     return 0;
 
-  pdfium::base::CheckedNumeric<FX_FILESIZE> new_pos = m_iPosition;
+  FX_SAFE_FILESIZE new_pos = m_iPosition;
   new_pos += iBufferSize;
   m_iPosition = new_pos.ValueOrDefault(m_iPosition);
   return new_pos.IsValid() ? iBufferSize : 0;

core/fxcrt/fx_number.cpp

diff --git a/core/fxcrt/fx_number.cpp b/core/fxcrt/fx_number.cpp
index 0a565be..9935451 100644
--- a/core/fxcrt/fx_number.cpp
+++ b/core/fxcrt/fx_number.cpp
@@ -9,6 +9,7 @@
 #include <limits>
 
 #include "core/fxcrt/fx_extension.h"
+#include "core/fxcrt/fx_safe_types.h"
 #include "core/fxcrt/fx_string.h"
 
 FX_Number::FX_Number()
@@ -37,7 +38,7 @@
   // actually an unsigned value. We use a uint32_t so we can deal with the
   // unsigned and then check for overflow if the user actually signed the value.
   // The Permissions flag is listed in Table 3.20 PDF 1.7 spec.
-  pdfium::base::CheckedNumeric<uint32_t> unsigned_val = 0;
+  FX_SAFE_UINT32 unsigned_val = 0;
   bool bNegative = false;
   size_t cc = 0;
   if (strc[0] == '+') {