Also install sysroot for building Node.

Previously install-sysroot.py relied on gyp. This should be fixed now.
This way, tools/node/fetch_deps.py can also be used to fetch
dependencies when building V8 to run V8 tests from a Node.js checkout.

R=machenbach@chromium.org

Change-Id: Ic4ee425d6ae744c32f604d14fbfdb0554a00c486
Reviewed-on: https://chromium-review.googlesource.com/962421
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51939}

DEPS

@@ -258,35 +258,35 @@ hooks = [
   {
     'name': 'sysroot_arm',
     'pattern': '.',
-    'condition': '(checkout_linux and checkout_arm) and not build_for_node',
+    'condition': '(checkout_linux and checkout_arm)',
     'action': ['python', 'v8/build/linux/sysroot_scripts/install-sysroot.py',
                '--arch=arm'],
   },
   {
     'name': 'sysroot_arm64',
     'pattern': '.',
-    'condition': '(checkout_linux and checkout_arm64) and not build_for_node',
+    'condition': '(checkout_linux and checkout_arm64)',
     'action': ['python', 'v8/build/linux/sysroot_scripts/install-sysroot.py',
                '--arch=arm64'],
   },
   {
     'name': 'sysroot_x86',
     'pattern': '.',
-    'condition': '(checkout_linux and (checkout_x86 or checkout_x64)) and not build_for_node',
+    'condition': '(checkout_linux and (checkout_x86 or checkout_x64))',
     'action': ['python', 'v8/build/linux/sysroot_scripts/install-sysroot.py',
                '--arch=x86'],
   },
   {
     'name': 'sysroot_mips',
     'pattern': '.',
-    'condition': '(checkout_linux and checkout_mips) and not build_for_node',
+    'condition': '(checkout_linux and checkout_mips)',
     'action': ['python', 'v8/build/linux/sysroot_scripts/install-sysroot.py',
                '--arch=mips'],
   },
   {
     'name': 'sysroot_x64',
     'pattern': '.',
-    'condition': '(checkout_linux and checkout_x64) and not build_for_node',
+    'condition': 'checkout_linux and checkout_x64',
     'action': ['python', 'v8/build/linux/sysroot_scripts/install-sysroot.py',
                '--arch=x64'],
   },