net: Move data reading functionalities from UploadElement to UploadElementReader
Add a new interface net::UploadElementReader and its implementations for bytes and file.
Rewrite UploadDataStream using UploadElementReader.
UploadElement::SetContentLength is replaced with UploadFileElementReader::ScopedOverridingContentLengthForTests.
HttpNetworkTransactionSpdy(2|3)Test.UnreadableUploadFileAfterAuthRestart is bit modified since a new FileStream is created every time when UploadDataStream is initialized.
BUG=145329
TEST=net_unittests
Review URL: https://chromiumcodereview.appspot.com/10868064
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@156113 0039d316-1c4b-4281-b951-d872f2087c98
16 files changed
