URLRequestJob: change ReadRawData contract

chrome/browser/chromeos/fileapi/external_file_url_request_job.h

Index: chrome/browser/chromeos/fileapi/external_file_url_request_job.h
diff --git a/chrome/browser/chromeos/fileapi/external_file_url_request_job.h b/chrome/browser/chromeos/fileapi/external_file_url_request_job.h
index a026e439b5e39b644ee45293cba0973447fbf710..6201a7734ead87fc4c6063b16de2fc96fa26f8a5 100644
--- a/chrome/browser/chromeos/fileapi/external_file_url_request_job.h
+++ b/chrome/browser/chromeos/fileapi/external_file_url_request_job.h
@@ -63,12 +63,13 @@ class ExternalFileURLRequestJob : public net::URLRequestJob {
   void Kill() override;
   bool GetMimeType(std::string* mime_type) const override;
   bool IsRedirectResponse(GURL* location, int* http_status_code) override;
-  bool ReadRawData(net::IOBuffer* buf, int buf_size, int* bytes_read) override;
+  int ReadRawData(net::IOBuffer* buf, int buf_size) override;
 
  protected:
   ~ExternalFileURLRequestJob() override;
 
  private:
+  void DoStart();
   // Called from an internal helper class defined in drive_url_request_job.cc,

[mtomasz, 2015/11/02 05:43:21]

nit: \n between #72 and #73.
nit: Please add a comment. It's not obvious why we have DoStart() besides
Start().

[xunjieli, 2015/11/02 15:40:11]

Done. I also renamed the method to make it clear that it should be invoked
asynchronously in Start.

   // which is running on the UI thread.
   void OnHelperResultObtained(
@@ -91,6 +92,7 @@ class ExternalFileURLRequestJob : public net::URLRequestJob {
   void* const profile_id_;
 
   // The range of the file to be returned.
+  net::Error range_parse_result_;
   net::HttpByteRange byte_range_;
   int64 remaining_bytes_;