d3d11: compile d3d11 backend in chromium build

So code search cross ref can work for d3d11 backend. Chrome webgpu
will only discover D3D12 device right now, so this build d3d11
backend should not break things.

Bug: dawn:1705
Change-Id: I2cb6753fe2be1588c9cf1190742f8169164d1662
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/131200
Reviewed-by: Austin Eng <enga@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Peng Huang <penghuang@chromium.org>

scripts/dawn_features.gni

@@ -55,7 +55,7 @@ declare_args() {
   dawn_complete_static_libs = false
 
   # Enables the compilation of Dawn's D3D11 backend
-  dawn_enable_d3d11 = is_win && !build_with_chromium
+  dawn_enable_d3d11 = is_win
 
   # Enables the compilation of Dawn's D3D12 backend
   dawn_enable_d3d12 = is_win