Revert "Don't build js2gtest()s in win/cross builds."

This reverts commit 3a54e6fa.

Reason for revert: Possibly no longer needed after
#703693 disabled g2gtest()s in cross builds in a different way.

Original change's description:
> Don't build js2gtest()s in win/cross builds.
> 
> Bug: 1010561
> Change-Id: Ic6b0d656af1944d9dbb16f5fb96d70fe1ad90f14
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1835157
> Auto-Submit: Nico Weber <thakis@chromium.org>
> Commit-Queue: Dan Beam <dbeam@chromium.org>
> Reviewed-by: Dan Beam <dbeam@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#702156}

TBR=thakis@chromium.org,dbeam@chromium.org

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

Bug: 1010561
Change-Id: I7b8fd3399786da5d51b827b846d2b03c72efb337
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1851085
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#704472}

chrome/test/base/js2gtest.gni

@@ -19,16 +19,7 @@ import("//v8/gni/v8.gni")
 #   defines
 #   deps
 #   visibility
-if (is_win && host_os != "win") {
-  # Running v8_shell for the host doesn't work in cross builds,
-  # https://crbug.com/1010561
-  template("js2gtest") {
-    not_needed(invoker, "*")
-    group(target_name) {
-    }
-  }
-} else {
-  template("js2gtest") {
+template("js2gtest") {
   assert(defined(invoker.test_type) &&
          (invoker.test_type == "webui" || invoker.test_type == "unit" ||
           invoker.test_type == "extension" ||
@@ -158,5 +149,4 @@ if (is_win && host_os != "win") {
       ]
     }
   }
-  }
 }