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}

chrome/test/base/js2gtest.gni

@@ -19,7 +19,16 @@ import("//v8/gni/v8.gni")
 #   defines
 #   deps
 #   visibility
-template("js2gtest") {
+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") {
     assert(defined(invoker.test_type) &&
            (invoker.test_type == "webui" || invoker.test_type == "unit" ||
             invoker.test_type == "extension" ||
@@ -149,4 +158,5 @@ template("js2gtest") {
         ]
       }
     }
+  }
 }

docs/win_cross.md

@@ -12,9 +12,8 @@ swarming.  This document describes how to set that up, and current restrictions.
 
 What does *not* work:
 
-* 64-bit renderer processes don't use V8 snapshots, slowing down their startup
-  ([bug](https://crbug.com/803591))
-* on Mac hosts, 32-bit builds don't use V8 snapshots either
+* `js2gtest` tests are omitted from the build ([bug](https://crbug.com/1010561))
+* on Mac hosts, 32-bit builds don't use V8 snapshots
   ([bug](https://crbug.com/794838) has more information, but this is unlikely
   to ever change)