Download unittest package from cloud storage.

The deprecated unittest package is version 0.11.6 of the test package.
Checking it out via git, alongside test, causes a git-cache locking conflict.

BUG=
R=sgjesse@google.com

Review URL: https://codereview.chromium.org/1631263002 .

DEPS

@@ -86,7 +86,6 @@ vars = {
   "test_tag": "@0.12.6+1",
   "test_reflective_loader_tag": "@0.0.3",
   "utf_rev": "@1f55027068759e2d52f2c12de6a57cce5f3c5ee6",
-  "unittest_tag": "@0.11.6",
   "usage_rev": "@b5080dac0d26a5609b266f8fdb0d053bc4c1c638",
   "watcher_tag": "@0.9.7",
   "when_tag": "@0.2.0+2",
@@ -256,8 +255,6 @@ deps = {
   Var("dart_root") + "/third_party/pkg/test_reflective_loader":
       (Var("github_mirror") % "test_reflective_loader") +
       Var("test_reflective_loader_tag"),
-  Var("dart_root") + "/third_party/pkg/unittest":
-      (Var("github_mirror") % "test") + Var("unittest_tag"),
   Var("dart_root") + "/third_party/pkg/usage":
       (Var("github_mirror") % "usage") + Var("usage_rev"),
   Var("dart_root") + "/third_party/pkg/utf":
@@ -383,6 +380,22 @@ hooks = [
       Var('dart_root') + "/third_party/pkg/petitparser.tar.gz.sha1",
     ],
   },
+  {
+    "name": "unittest",
+    # Unittest is an early version, 0.11.6, of the package "test"
+    # Do not use it in any new tests.
+    "pattern": ".",
+    "action": [
+      "download_from_google_storage",
+      "--no_auth",
+      "--no_resume",
+      "--bucket",
+      "dart-dependencies",
+      "--extract",
+      "-s",
+      Var('dart_root') + "/third_party/pkg/unittest.tar.gz.sha1",
+    ],
+  },
   {
     "name": "7zip",
     "pattern": ".",

third_party/.gitignore

@@ -11,4 +11,5 @@
 !7zip.tar.gz.sha1
 !firefox_jsshell
 !gsutil.tar.gz.sha1
-!clang.tar.gz.sha1
+!clang.tar.gz.sha1
+!unittest.tar.gz.sha1

third_party/pkg/unittest.tar.gz.sha1

@@ -0,0 +1 @@
+fc9b8ccbfbecf20257255d69693d5a50f8692757