[Blob] BlobReader class & tests, and removal of all redundant reading.

net/base/upload_element_reader.h

Index: net/base/upload_element_reader.h
diff --git a/net/base/upload_element_reader.h b/net/base/upload_element_reader.h
index 267df8c89d3a9013100d56b9d0c56a318959b7f1..56821f653a1619f8e95e9ffa3a2fc5e3b9bd737b 100644
--- a/net/base/upload_element_reader.h
+++ b/net/base/upload_element_reader.h
@@ -9,11 +9,14 @@
 #include "net/base/completion_callback.h"
 #include "net/base/net_export.h"
 
+namespace storage {
+class UploadBlobElementReader;
+}
+
 namespace net {
 
 class IOBuffer;
 class UploadBytesElementReader;
-class UploadDiskCacheEntryElementReader;
 class UploadFileElementReader;
 
 // An interface to read an upload data element.
@@ -24,8 +27,8 @@ class NET_EXPORT UploadElementReader {
 
   // Returns this instance's pointer as UploadDiskCacheEntryElementReader when
   // possible, otherwise returns nullptr.
-  virtual const UploadDiskCacheEntryElementReader*
-  AsDiskCacheEntryReaderForTests() const;
+  virtual const storage::UploadBlobElementReader*
+  AsUploadBlobElementReaderForTests() const;

[mmenke, 2015/09/14 19:24:33]

This method is a layering violation.  Net shouldn't know what an upload blob
element reader is.  I'd suggest just casting instead, much as I dislike explicit
casting.

[dmurph, 2015/09/14 20:27:50]

Sounds good.  Done.

 
   // Returns this instance's pointer as UploadBytesElementReader when possible,
   // otherwise returns NULL.