Fix silent truncations when extracting values from CheckedNumeric

device/hid/hid_connection_mac.cc

 // Copyright (c) 2014 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.
 
 #include "device/hid/hid_connection_mac.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/mac/foundation_util.h"
 #include "base/numerics/safe_math.h"
@@ skipping 118 matching lines @@
                                            CFIndex report_length) {
   HidConnectionMac* connection = static_cast<HidConnectionMac*>(context);
   if (result != kIOReturnSuccess) {
     HID_LOG(EVENT) << "Failed to read input report: " << HexErrorCode(result);
     return;
   }
 
   scoped_refptr<net::IOBufferWithSize> buffer;
   if (connection->device_info()->has_report_id()) {
     // report_id is already contained in report_bytes
-    buffer = new net::IOBufferWithSize(
-        base::CheckedNumeric<size_t>(report_length).ValueOrDie());
+    buffer =
+        new net::IOBufferWithSize(base::checked_cast<size_t>(report_length));
     memcpy(buffer->data(), report_bytes, report_length);
   } else {
-    buffer = new net::IOBufferWithSize(
-        (base::CheckedNumeric<size_t>(report_length) + 1).ValueOrDie());
+    buffer = new net::IOBufferWithSize(static_cast<size_t>(
+        (base::CheckedNumeric<size_t>(report_length) + 1).ValueOrDie()));
     buffer->data()[0] = 0;
     memcpy(buffer->data() + 1, report_bytes, report_length);
   }
 
   connection->ProcessInputReport(buffer);
 }
 
 void HidConnectionMac::ProcessInputReport(
     scoped_refptr<net::IOBufferWithSize> buffer) {
   DCHECK(thread_checker().CalledOnValidThread());
@@ skipping 82 matching lines @@
                                       this,
                                       base::Bind(callback, false)));
   }
 }
 
 void HidConnectionMac::ReturnAsyncResult(const base::Closure& callback) {
   callback.Run();
 }
 
 }  // namespace device