Enable more `gn check` results.

This PR fixes one gn include issue and widens the GN check results
to test all but one of the GN targets. The remaining target is
disabled due to our absl configuration.

Bug: dawn:1372
Change-Id: I6e92a7aa777c3508e57d1e7138c73b7a92756db1
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/88680
Reviewed-by: Brandon Jones <bajones@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
diff --git a/.gn b/.gn
index 45527a5..7726b98 100644
--- a/.gn
+++ b/.gn
@@ -34,10 +34,7 @@
   vma_vulkan_headers_dir = "//third_party/vulkan-deps/vulkan-headers/src"
 }
 
-check_targets = [
-  # Everything in BUILD.gn
-  "//:*",
-
-  # Everything in third_party/BUILD.gn
-  "//third_party/:*",
+no_check_targets = [
+  # TODO(crbug.com/dawn/1404): Issue with the Absl headers
+  "//src/dawn/tests:dawn_unittests",
 ]
diff --git a/src/dawn/samples/BUILD.gn b/src/dawn/samples/BUILD.gn
index 26067fe..58874cf 100644
--- a/src/dawn/samples/BUILD.gn
+++ b/src/dawn/samples/BUILD.gn
@@ -34,6 +34,7 @@
   # Export all of these as public deps so that `gn check` allows includes
   public_deps = [
     "${dawn_root}/src/dawn:cpp",
+    "${dawn_root}/src/dawn:proc_shared",
     "${dawn_root}/src/dawn/common",
     "${dawn_root}/src/dawn/native",
     "${dawn_root}/src/dawn/utils",