Reland "Add WebGPU to about:flags on Windows"

This is a reland of 953678c57932ee752114ae5381fd9dc063e4f816

Win7 tests are now correctly handled

Original change's description:
> Add WebGPU to about:flags on Windows
>
> Now that all of the work on the Chromium and Dawn side to support
> Windows has been complete, we need to add WebGPU to about:flags
> on Windows.
>
> Bug: 966580
> Change-Id: I41d9f892be0d849c5ece1d5569f98344a7a92a1e
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1873383
> Reviewed-by: Sunny Sachanandani <[email protected]>
> Commit-Queue: Rafael Cintron <[email protected]>
> Cr-Commit-Position: refs/heads/master@{#708405}

Bug: 966580
Change-Id: I5cad4fbc9d7c1960a5d2b1b2c7e4e0e2f774c7ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1892156
Reviewed-by: Zhenyao Mo <[email protected]>
Commit-Queue: Rafael Cintron <[email protected]>
Cr-Commit-Position: refs/heads/master@{#711372}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 77c67a5..ffe51619 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -4166,7 +4166,7 @@
      FEATURE_VALUE_TYPE(
          autofill::features::kAutofillDoNotMigrateUnsupportedLocalCards)},
     {"enable-unsafe-webgpu", flag_descriptions::kUnsafeWebGPUName,
-     flag_descriptions::kUnsafeWebGPUDescription, kOsMac,
+     flag_descriptions::kUnsafeWebGPUDescription, kOsMac | kOsWin,
      SINGLE_VALUE_TYPE(switches::kEnableUnsafeWebGPU)},
 
 #if defined(OS_ANDROID)