Prep for update to latest QEMU version

Prep for update to latest QEMU version

Remove dependency of checked-in qemu tarball.  Instead
download tarball on demand and verify with SHA1 sum.

Once this lands there is a corresponding change to the
third_party repository needed before we can update to
2.3.0: https://codereview.chromium.org/1105003003/

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4157
R=bradnelson@google.com

Committed: https://chromium.googlesource.com/native_client/src/native_client/+/91f01b73180d713eca02648414b333922c01e5cd

[Sam Clegg, 2015-04-28 20:39:45]

sbc@chromium.org changed reviewers:
+ bradnelson@chromium.org

[bradn, 2015-04-28 20:46:16]

bradnelson@google.com changed reviewers:
+ bradnelson@google.com

[bradn, 2015-04-28 20:46:16]

lgtm

https://codereview.chromium.org/1109163004/diff/1/tools/trusted_cross_toolcha...
File tools/trusted_cross_toolchains/trusted-toolchain-creator.armhf.trusty.sh
(right):

https://codereview.chromium.org/1109163004/diff/1/tools/trusted_cross_toolcha...
tools/trusted_cross_toolchains/trusted-toolchain-creator.armhf.trusty.sh:431:
wget -O ${TMP}/${QEMU_TARBALL} $QEMU_URL
curl?

[Sam Clegg, 2015-04-28 21:08:32]

https://codereview.chromium.org/1109163004/diff/1/tools/trusted_cross_toolcha...
File tools/trusted_cross_toolchains/trusted-toolchain-creator.armhf.trusty.sh
(right):

https://codereview.chromium.org/1109163004/diff/1/tools/trusted_cross_toolcha...
tools/trusted_cross_toolchains/trusted-toolchain-creator.armhf.trusty.sh:431:
wget -O ${TMP}/${QEMU_TARBALL} $QEMU_URL
On 2015/04/28 20:46:16, bradn wrote:
> curl?

Any reason why thats better?

[bradn, 2015-04-28 21:11:08]

https://codereview.chromium.org/1109163004/diff/1/tools/trusted_cross_toolcha...
File tools/trusted_cross_toolchains/trusted-toolchain-creator.armhf.trusty.sh
(right):

https://codereview.chromium.org/1109163004/diff/1/tools/trusted_cross_toolcha...
tools/trusted_cross_toolchains/trusted-toolchain-creator.armhf.trusty.sh:431:
wget -O ${TMP}/${QEMU_TARBALL} $QEMU_URL
On 2015/04/28 20:46:16, bradn wrote:
> curl?

consistency, I thought we use curl in most places.
But actually at a glance nacl's an even split
it's in naclports we just use curl.
So, nevermind.

[Sam Clegg, 2015-04-28 21:20:14]

Committed patchset #1 (id:1) manually as
91f01b73180d713eca02648414b333922c01e5cd (presubmit successful).