[v8][wasm] Enable testing of trap handlers on Windows

The field trial should be turned on by http://cl/220249819.

R=mpearson@chromium.org

Change-Id: Ifa0b4c5d7c9850c304bc4d2ce5b4fb44328f85da
Reviewed-on: https://chromium-review.googlesource.com/c/1318910
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607529}

chrome/test/v8/wasm_trap_handler_browsertest.cc

@@ -18,10 +18,13 @@
 namespace {
 // |kIsTrapHandlerSupported| indicates whether the trap handler is supported
 // (i.e. allowed to be enabled) on the currently platform. Currently we only
-// support non-Android, Linux x64. In the future more platforms will be
-// supported. Though this file is a browser test that is not built on Android.
+// support non-Android, Linux x64, and Windows x64. In the future more platforms
+// will be supported. Though this file is a browser test that is not built on
+// Android.
 #if defined(OS_LINUX) && defined(ARCH_CPU_X86_64)
 constexpr bool kIsTrapHandlerSupported = true;
+#elif defined(OS_WIN) && defined(ARCH_CPU_X86_64)
+constexpr bool kIsTrapHandlerSupported = true;
 #else
 constexpr bool kIsTrapHandlerSupported = false;
 #endif

testing/variations/fieldtrial_testing_config.json

@@ -5149,7 +5149,8 @@
     "V8WasmTrapHandler": [
         {
             "platforms": [
-                "linux"
+                "linux",
+                "windows"
             ],
             "experiments": [
                 {