Add remaining trivial targets for the Linux GN build

gpu/BUILD.gn

Index: gpu/BUILD.gn
diff --git a/gpu/BUILD.gn b/gpu/BUILD.gn
index 830464e93f181d272026f62147607e01b25e5e36..7c9d732e5bb516f45068a0390ba225af5bbd2ef1 100644
--- a/gpu/BUILD.gn
+++ b/gpu/BUILD.gn
@@ -34,6 +34,7 @@
 # gpu/skia_bindings/skia_bindings.gyp:gpu_skia_bindings => //gpu/skia_bindings
 
 import("//testing/test.gni")
+import("//build/config/ui.gni")
 
 component("gpu") {
   public_deps = [
@@ -282,3 +283,25 @@ test("angle_unittests") {
     "//third_party/angle:translator_static",
   ]
 }
+
+if (is_linux && !is_chromeos && target_cpu != "arm" && use_x11) {
+  executable("compositor_model_bench") {
+    sources = [
+      "tools/compositor_model_bench/compositor_model_bench.cc",
+      "tools/compositor_model_bench/forward_render_model.cc",
+      "tools/compositor_model_bench/render_model_utils.cc",
+      "tools/compositor_model_bench/render_models.cc",
+      "tools/compositor_model_bench/render_tree.cc",
+      "tools/compositor_model_bench/shaders.cc",
+    ]
+
+    libs = [ "GL" ]
+
+    configs += [ "//build/config/linux:x11" ]
+
+    deps = [
+      "//base",
+      "//ui/gl",
+    ]
+  }
+}