RTC_[D]CHECK_op: Remove superfluous casts

webrtc/base/file_posix.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 63 matching lines @@
                      offset + total_read);
     } while (read == -1 && errno == EINTR);
     if (read == -1)
       break;
     total_read += read;
   } while (total_read < length);
   return total_read;
 }
 
 bool File::Seek(size_t offset) {
-  RTC_DCHECK_LE(offset, static_cast<size_t>(std::numeric_limits<off_t>::max()));
+  RTC_DCHECK_LE(offset, std::numeric_limits<off_t>::max());
   return lseek(file_, static_cast<off_t>(offset), SEEK_SET) != -1;
 }
 
 bool File::Close() {
   if (file_ == rtc::kInvalidPlatformFileValue)
     return false;
   bool ret = close(file_) == 0;
   file_ = rtc::kInvalidPlatformFileValue;
   return ret;
 }
 
 }  // namespace rtc