Fix int overflow in blob_url_request_job when we read files > 2GB

webkit/blob/blob_url_request_job.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 "webkit/blob/blob_url_request_job.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/file_util_proxy.h"
 #include "base/message_loop.h"
@@ skipping 396 matching lines @@
   int bytes_read = read_buf_->BytesConsumed();
   read_buf_ = NULL;
   return bytes_read;
 }
 
 int BlobURLRequestJob::ComputeBytesToRead() const {
   int64 current_item_remaining_bytes =
       item_length_list_[current_item_index_] - current_item_offset_;
   int64 remaining_bytes = std::min(current_item_remaining_bytes,
                                    remaining_bytes_);
-  return std::min(read_buf_->BytesRemaining(),
-                  static_cast<int>(remaining_bytes));
+
+  return static_cast<int>(std::min(
+             static_cast<int64>(read_buf_->BytesRemaining()),
+             remaining_bytes));
 }
 
 bool BlobURLRequestJob::ReadLoop(int* bytes_read) {
   // Read until we encounter an error or could not get the data immediately.
   while (remaining_bytes_ > 0 && read_buf_->BytesRemaining() > 0) {
     if (!ReadItem())
       return false;
   }
 
   *bytes_read = BytesReadCompleted();
@@ skipping 102 matching lines @@
         file_thread_proxy_,
         item.file_path,
         item.offset,
         item.expected_modification_time);
   }
   DCHECK(index_to_reader_[index]);
   return index_to_reader_[index];
 }
 
 }  // namespace webkit_blob