net: Use FileStream asynchronously from UploadFileElementReader

InitInternal() and ReadInternal() were used to share the same implementation with UploadFileElementReaderSync.
There is no need to maintain them since UploadFileElementReaderSync is gone.
Abandon these unneeded functions and use FileStream in an asynchronous way.

BUG=294797
TEST=net_unittests

Review URL: https://codereview.chromium.org/139253002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245509 0039d316-1c4b-4281-b951-d872f2087c98
Roll grit to revision 147.

147: Added support for Android and iOS to the grit policy generators.

BUG=None

Review URL: https://codereview.chromium.org/136793019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245510 0039d316-1c4b-4281-b951-d872f2087c98
Update V8 to version 3.24.18.

TBR=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/137113004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245511 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245512 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245512