Revert "Fuchsia: use CIPD to check out arch-specific QEMU binaries."

This reverts commit 0f06f8fd.

Reason for revert: CIPD doesn't allow multiple .ensure files to coexist, crbug.com/789809

Original change's description:
> Fuchsia: use CIPD to check out arch-specific QEMU binaries.
> 
> These binaries allow us to run QEMU on ARM; the current deployment
> in the Fuchsia SDK folder is x86-64 only.
> 
> The "qemu" folder can safely be removed from the Fuchsia SDK
> once this CL lands and the trybots are confirmed to still be in
> working order.
> 
> Also modify the runner script to use arch-specific QEMU binaries.
> 
> 
> Bug: 786193
> Change-Id: I1515bdf330f496ff47f88ba3b131629d4e24fea3
> Reviewed-on: https://chromium-review.googlesource.com/783699
> Commit-Queue: Kevin Marshall <kmarshall@chromium.org>
> Reviewed-by: Dirk Pranke <dpranke@chromium.org>
> Reviewed-by: Scott Graham <scottmg@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#519536}

TBR=dpranke@chromium.org,kmarshall@chromium.org,scottmg@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 786193
Change-Id: I320cf80f222c337b38e91e0f10ef2a3479f45f9d
Reviewed-on: https://chromium-review.googlesource.com/810088
Commit-Queue: Kevin Marshall <kmarshall@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Kevin Marshall <kmarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521990}

DEPS

@@ -1310,16 +1310,6 @@ hooks = [
     ],
   },
 
-  {
-    'name': 'Fuchsia QEMU ensure',
-    'pattern': '.',
-    'condition': 'checkout_fuchsia',
-    'action': ['src/build/cipd/cipd_wrapper.py',
-               '--chromium-root', 'src',
-               '--ensure-file', 'src/build/cipd/fuchsia/qemu.ensure',
-    ],
-  },
-
   # Download and initialize "vpython" VirtualEnv environment packages.
   {
     'name': 'vpython_common',

build/cipd/fuchsia/OWNERS

-file://build/fuchsia/OWNERS

build/cipd/fuchsia/qemu.ensure

-# Copyright 2017 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-@Subdir third_party/qemu-aarch64
-fuchsia/qemu/linux-arm64 5c0de765eec81c8587d363121a0fdac3ed17313e
-
-@Subdir third_party/qemu-x86_64
-fuchsia/qemu/linux-amd64 ff5977bcc054ab81e4f1b887f89b690f86fad969

build/config/fuchsia/rules.gni

@@ -55,8 +55,6 @@ template("generate_runner_script") {
       "//build/fuchsia/runner_common.py",
       "//build/util/lib/",
       "//third_party/fuchsia-sdk/",
-      "//third_party/qemu-aarch64/",
-      "//third_party/qemu-x86_64/",
     ]
 
     runner_args += [

build/fuchsia/runner_common.py

@@ -24,8 +24,6 @@ import uuid
 DIR_SOURCE_ROOT = os.path.abspath(
     os.path.join(os.path.dirname(__file__), os.pardir, os.pardir))
 SDK_ROOT = os.path.join(DIR_SOURCE_ROOT, 'third_party', 'fuchsia-sdk')
-QEMU_ROOT = os.path.join(DIR_SOURCE_ROOT, 'third_party',
-                         'qemu-' + platform.machine())
 
 # The guest will get 192.168.3.9 from DHCP, while the host will be
 # accessible as 192.168.3.2 .
@@ -656,7 +654,7 @@ def RunFuchsia(bootfs_data, use_device, kernel_path, dry_run,
         stdout=subprocess.PIPE, stdin=open(os.devnull))
   else:
     qemu_path = os.path.join(
-        QEMU_ROOT,'bin',
+        SDK_ROOT, 'qemu', 'bin',
         'qemu-system-' + _TargetCpuToArch(bootfs_data.target_cpu))
     qemu_command = [qemu_path,
         '-m', '2048',

third_party/.gitignore

@@ -159,8 +159,6 @@
 /python_26
 /pywebsocket/src
 /pywebsocket/src
-/qemu-aarch64
-/qemu-x86_64
 /re2/src
 /requests/src
 /robolectric/lib/