Fix pdfium use of base/numerics

pdf/pdfium/pdfium_api_string_buffer_adapter.h

 // Copyright 2015 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 PDF_PDFIUM_PDFIUM_API_STRING_BUFFER_ADAPTER_H_
 #define PDF_PDFIUM_PDFIUM_API_STRING_BUFFER_ADAPTER_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
@@ skipping 24 matching lines @@
   // pointer has space to write a null-terminator.
   void* GetData();
 
   // Resizes |str_| to |actual_size| - 1 characters, thereby removing the extra
   // null-terminator. This must be called prior to the adapter's destruction.
   // The pointer returned by GetData() should be considered invalid.
   void Close(size_t actual_size);
 
   template <typename IntType>
   void Close(IntType actual_size) {
-    base::CheckedNumeric<size_t> unsigned_size = actual_size;
-    Close(unsigned_size.ValueOrDie());
+    Close(base::checked_cast<size_t>(actual_size));
   }
 
  private:
   StringType* const str_;
   void* const data_;
   const size_t expected_size_;
   const bool check_expected_size_;
   bool is_closed_;
 
   DISALLOW_COPY_AND_ASSIGN(PDFiumAPIStringBufferAdapter);
@@ skipping 24 matching lines @@
   void* GetData();
 
   // Resizes |str_| to |actual_size| - sizeof(StringType::value_type) bytes,
   // thereby removing the extra null-terminator. This must be called prior to
   // the adapter's destruction. The pointer returned by GetData() should be
   // considered invalid.
   void Close(size_t actual_size);
 
   template <typename IntType>
   void Close(IntType actual_size) {
-    base::CheckedNumeric<size_t> unsigned_size = actual_size;
-    Close(unsigned_size.ValueOrDie());
+    Close(base::checked_cast<size_t>(actual_size));
   }
 
  private:
   PDFiumAPIStringBufferAdapter<StringType> adapter_;
 };
 
 }  // namespace chrome_pdf
 
 #endif  // PDF_PDFIUM_PDFIUM_API_STRING_BUFFER_ADAPTER_H_