Implement GetUploadStatusOperation on GData WAPI.

chrome/browser/google_apis/base_operations.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 "chrome/browser/google_apis/base_operations.h"
 
 #include "base/json/json_reader.h"
 #include "base/stringprintf.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/task_runner_util.h"
@@ skipping 459 matching lines @@
   return URLFetcher::PUT;
 }
 
 void UploadRangeOperationBase::ProcessURLFetchResults(
     const URLFetcher* source) {
   GDataErrorCode code = GetErrorCode(source);
   net::HttpResponseHeaders* hdrs = source->GetResponseHeaders();
 
   if (code == HTTP_RESUME_INCOMPLETE) {
     // Retrieve value of the first "Range" header.
-    int64 start_position_received = -1;
-    int64 end_position_received = -1;
+    // The Range header is appeared only if there is at least one received
+    // byte. So, initialize the positions by 0 so that the [0,0) will be
+    // returned via the |callback_| for empty data case.
+    int64 start_position_received = 0;
+    int64 end_position_received = 0;
     std::string range_received;
     hdrs->EnumerateHeader(NULL, kUploadResponseRange, &range_received);
     if (!range_received.empty()) {  // Parse the range header.
       std::vector<net::HttpByteRange> ranges;
       if (net::HttpUtil::ParseRangeHeader(range_received, &ranges) &&
           !ranges.empty() ) {
         // We only care about the first start-end pair in the range.
         //
         // Range header represents the range inclusively, while we are treating
         // ranges exclusively (i.e., end_position_received should be one passed
         // the last valid index). So "+ 1" is added.
         start_position_received = ranges[0].first_byte_position();
         end_position_received = ranges[0].last_byte_position() + 1;
       }
     }
+    // The Range header has the received data range, so the start position
+    // should be always 0.
+    DCHECK_EQ(start_position_received, 0);
     DVLOG(1) << "Got response for [" << drive_file_path_.value()
              << "]: code=" << code
              << ", range_hdr=[" << range_received
              << "], range_parsed=" << start_position_received
              << "," << end_position_received;
 
     OnRangeOperationComplete(UploadRangeResponse(code,
                                                  start_position_received,
                                                  end_position_received),
                              scoped_ptr<base::Value>());
@@ skipping 110 matching lines @@
 
   download_action_callback_.Run(code, temp_file);
   OnProcessURLFetchResultsComplete(code == HTTP_SUCCESS);
 }
 
 void DownloadFileOperation::RunCallbackOnPrematureFailure(GDataErrorCode code) {
   download_action_callback_.Run(code, base::FilePath());
 }
 
 }  // namespace google_apis