Fix StringFileWriter::Seek()

util/file/string_file_writer.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 92 matching lines @@
 
     case SEEK_END:
       base_offset = string_.size();
       break;
 
     default:
       LOG(ERROR) << "Seek(): invalid whence " << whence;
       return -1;
   }
 
-  off_t offset_offt;
-  if (!AssignIfInRange(&offset_offt, base_offset)) {
+  off_t base_offset_offt;
+  if (!AssignIfInRange(&base_offset_offt, base_offset)) {
     LOG(ERROR) << "Seek(): base_offset " << base_offset << " invalid for off_t";
     return -1;
   }
-
-  base::CheckedNumeric<off_t> new_offset(offset_offt);
+  base::CheckedNumeric<off_t> new_offset(base_offset_offt);
   new_offset += offset;
   if (!new_offset.IsValid()) {
     LOG(ERROR) << "Seek(): new_offset invalid";
     return -1;
   }
-
-  if (!AssignIfInRange(&offset_offt, new_offset.ValueOrDie())) {
-    LOG(ERROR) << "Seek(): new_offset " << new_offset.ValueOrDie()
+  off_t new_offset_offt = new_offset.ValueOrDie();
+  size_t new_offset_sizet;
+  if (!AssignIfInRange(&new_offset_sizet, new_offset_offt)) {
+    LOG(ERROR) << "Seek(): new_offset " << new_offset_offt
                << " invalid for size_t";
     return -1;
   }
 
-  offset_ = offset_offt;
+  offset_ = new_offset_sizet;
 
   return offset_.ValueOrDie();
 }
 
 }  // namespace crashpad