Fix silent truncations when extracting values from CheckedNumeric

content/browser/appcache/appcache_response.cc

 // Copyright (c) 2012 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 "content/browser/appcache/appcache_response.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 266 matching lines @@
 
       // Also return the size of the response body
       DCHECK(entry_);
       info_buffer_->response_data_size =
           entry_->GetSize(kResponseContentIndex);
 
       int64_t metadata_size = entry_->GetSize(kResponseMetadataIndex);
       if (metadata_size > 0) {
         reading_metadata_size_ = metadata_size;
         info_buffer_->http_info->metadata = new net::IOBufferWithSize(
-            base::CheckedNumeric<size_t>(metadata_size).ValueOrDie());
+            base::checked_cast<size_t>(metadata_size));
         ReadRaw(kResponseMetadataIndex, 0,
                 info_buffer_->http_info->metadata.get(), metadata_size);
         return;
       }
     } else {
       read_position_ += result;
     }
   }
   InvokeUserCompletionCallback(result);
 }
@@ skipping 188 matching lines @@
   }
   WriteRaw(kResponseMetadataIndex, 0, buffer_.get(), write_amount_);
 }
 
 void AppCacheResponseMetadataWriter::OnIOComplete(int result) {
   DCHECK(result < 0 || write_amount_ == result);
   InvokeUserCompletionCallback(result);
 }
 
 }  // namespace content