diff --git a/.gn b/.gn
index 09e3d24..3860440 100644
--- a/.gn
+++ b/.gn
@@ -40,4 +40,10 @@
   vma_vulkan_headers_dir = "//third_party/vulkan-deps/vulkan-headers/src"
 }
 
-check_targets = [ "//*" ]
+check_targets = [
+  # Everything in BUILD.gn
+  "//:*",
+
+  # Everything in third_party/BUILD.gn
+  "//third_party/:*",
+]
diff --git a/src/dawn/samples/BUILD.gn b/src/dawn/samples/BUILD.gn
index 58874cf..26067fe 100644
--- a/src/dawn/samples/BUILD.gn
+++ b/src/dawn/samples/BUILD.gn
@@ -34,7 +34,6 @@
   # 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",
     "${dawn_root}/src/dawn/utils",
diff --git a/src/dawn/tests/BUILD.gn b/src/dawn/tests/BUILD.gn
index 052ab07..0fee0dd 100644
--- a/src/dawn/tests/BUILD.gn
+++ b/src/dawn/tests/BUILD.gn
@@ -186,7 +186,6 @@
     "${dawn_root}/src/dawn/native:static",
     "${dawn_root}/src/dawn/utils",
     "${dawn_root}/src/dawn/wire",
-    "${dawn_root}/third_party/gn/abseil-cpp:strings",
   ]
 
   # Add internal dawn native config for internal unittests.
diff --git a/third_party/gn/abseil-cpp/BUILD.gn b/third_party/gn/abseil-cpp/BUILD.gn
index 4561dfd..6b4017e 100644
--- a/third_party/gn/abseil-cpp/BUILD.gn
+++ b/third_party/gn/abseil-cpp/BUILD.gn
@@ -39,99 +39,18 @@
 }
 
 #
-# absl/algorithm
-#
-
-absl_source_set("algorithm") {
-  public = [ "${dawn_abseil_dir}/absl/algorithm/algorithm.h" ]
-  deps = [ ":config" ]
-}
-
-#
 # absl/base
 #
 
-absl_source_set("atomic_hook") {
-  public = [ "${dawn_abseil_dir}/absl/base/internal/atomic_hook.h" ]
-  public_deps = [
-    ":config",
-    ":core_headers",
-  ]
-}
-
-absl_source_set("base") {
-  public = [ "${dawn_abseil_dir}/absl/base/casts.h" ]
-  public_deps = [
-    ":atomic_hook",
-    ":base_internal",
-    ":config",
-    ":core_headers",
-    ":log_severity",
-    ":raw_logging_internal",
-    ":type_traits",
-  ]
-}
-
-absl_source_set("base_internal") {
-  public = [
-    "${dawn_abseil_dir}/absl/base/internal/identity.h",
-    "${dawn_abseil_dir}/absl/base/internal/inline_variable.h",
-    "${dawn_abseil_dir}/absl/base/internal/invoke.h",
-  ]
-  public_deps = [
-    ":config",
-    ":type_traits",
-  ]
-}
-
-absl_source_set("config") {
-  public = [
-    "${dawn_abseil_dir}/absl/base/config.h",
-    "${dawn_abseil_dir}/absl/base/options.h",
-    "${dawn_abseil_dir}/absl/base/policy_checks.h",
-  ]
-}
-
-absl_source_set("core_headers") {
-  public = [
-    "${dawn_abseil_dir}/absl/base/attributes.h",
-    "${dawn_abseil_dir}/absl/base/macros.h",
-    "${dawn_abseil_dir}/absl/base/optimization.h",
-    "${dawn_abseil_dir}/absl/base/port.h",
-  ]
-  public_deps = [ ":config" ]
-}
-
-absl_source_set("endian") {
-  public = [
-    "${dawn_abseil_dir}/absl/base/internal/endian.h",
-    "${dawn_abseil_dir}/absl/base/internal/unaligned_access.h",
-  ]
-  public_deps = [
-    ":base",
-    ":config",
-    ":core_headers",
-  ]
-}
-
 absl_source_set("log_severity") {
   sources = [ "${dawn_abseil_dir}/absl/base/log_severity.cc" ]
   public = [ "${dawn_abseil_dir}/absl/base/log_severity.h" ]
-  public_deps = [
-    ":config",
-    ":core_headers",
-  ]
 }
 
 absl_source_set("raw_logging_internal") {
   sources = [ "${dawn_abseil_dir}/absl/base/internal/raw_logging.cc" ]
   public = [ "${dawn_abseil_dir}/absl/base/internal/raw_logging.h" ]
-  public_deps = [
-    ":atomic_hook",
-    ":config",
-    ":core_headers",
-    ":log_severity",
-  ]
+  public_deps = [ ":log_severity" ]
   visibility = [ ":*" ]
 }
 
@@ -143,55 +62,9 @@
 }
 
 #
-# absl/functional
-#
-
-absl_source_set("function_ref") {
-  public = [ "${dawn_abseil_dir}/absl/functional/function_ref.h" ]
-  sources = [ "${dawn_abseil_dir}/absl/functional/internal/function_ref.h" ]
-  deps = [
-    ":base_internal",
-    ":core_headers",
-    ":type_traits",
-  ]
-}
-
-#
-# absl/memory
-#
-
-absl_source_set("memory") {
-  public = [ "${dawn_abseil_dir}/absl/memory/memory.h" ]
-  deps = [
-    ":core_headers",
-    ":type_traits",
-  ]
-}
-
-#
-# absl/meta
-#
-
-absl_source_set("type_traits") {
-  public = [ "${dawn_abseil_dir}/absl/meta/type_traits.h" ]
-  deps = [ ":config" ]
-}
-
-#
 # absl/numeric
 #
 
-absl_source_set("bits") {
-  public = [
-    "${dawn_abseil_dir}/absl/numeric/bits.h",
-    "${dawn_abseil_dir}/absl/numeric/internal/bits.h",
-  ]
-  deps = [
-    ":config",
-    ":core_headers",
-  ]
-}
-
 absl_source_set("int128") {
   sources = [
     "${dawn_abseil_dir}/absl/numeric/int128.cc",
@@ -199,16 +72,6 @@
     "${dawn_abseil_dir}/absl/numeric/int128_no_intrinsic.inc",
   ]
   public = [ "${dawn_abseil_dir}/absl/numeric/int128.h" ]
-  deps = [
-    ":bits",
-    ":config",
-    ":core_headers",
-  ]
-}
-
-absl_source_set("representation") {
-  public = [ "${dawn_abseil_dir}/absl/numeric/internal/representation.h" ]
-  deps = [ ":config" ]
 }
 
 #
@@ -253,16 +116,10 @@
     "${dawn_abseil_dir}/absl/strings/substitute.h",
   ]
   deps = [
-    ":base",
-    ":bits",
-    ":config",
-    ":core_headers",
-    ":endian",
     ":int128",
     ":raw_logging_internal",
     ":strings_internal",
     ":throw_delegate",
-    ":type_traits",
   ]
 }
 
@@ -279,13 +136,7 @@
     "${dawn_abseil_dir}/absl/strings/internal/resize_uninitialized.h",
     "${dawn_abseil_dir}/absl/strings/internal/utf8.h",
   ]
-  deps = [
-    ":config",
-    ":core_headers",
-    ":endian",
-    ":raw_logging_internal",
-    ":type_traits",
-  ]
+  deps = [ ":raw_logging_internal" ]
 }
 
 absl_source_set("str_format") {
@@ -313,63 +164,7 @@
   ]
   visibility = [ ":*" ]
   deps = [
-    ":bits",
-    ":core_headers",
-    ":function_ref",
     ":int128",
-    ":optional",
-    ":representation",
-    ":span",
     ":strings",
-    ":type_traits",
-  ]
-}
-
-#
-# absl/types
-#
-
-absl_source_set("bad_optional_access") {
-  sources = [ "${dawn_abseil_dir}/absl/types/bad_optional_access.cc" ]
-  public = [ "${dawn_abseil_dir}/absl/types/bad_optional_access.h" ]
-  public_deps = [ ":config" ]
-  deps = [ ":raw_logging_internal" ]
-}
-
-absl_source_set("optional") {
-  public = [ "${dawn_abseil_dir}/absl/types/optional.h" ]
-  sources = [ "${dawn_abseil_dir}/absl/types/internal/optional.h" ]
-  public_deps = [
-    ":bad_optional_access",
-    ":base_internal",
-    ":config",
-    ":core_headers",
-    ":memory",
-    ":type_traits",
-    ":utility",
-  ]
-}
-
-absl_source_set("span") {
-  public = [ "${dawn_abseil_dir}/absl/types/span.h" ]
-  sources = [ "${dawn_abseil_dir}/absl/types/internal/span.h" ]
-  public_deps = [
-    ":algorithm",
-    ":core_headers",
-    ":throw_delegate",
-    ":type_traits",
-  ]
-}
-
-#
-# absl/utility
-#
-
-absl_source_set("utility") {
-  public = [ "${dawn_abseil_dir}/absl/utility/utility.h" ]
-  deps = [
-    ":base_internal",
-    ":config",
-    ":type_traits",
   ]
 }