BUILD.gn: Add a dawn_samples group

BUG=

Change-Id: I328bdc960bfc28a1ea16ca0c6705cb60b929109f
Reviewed-on: https://dawn-review.googlesource.com/1542
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Stephen White <senorblanco@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index dc6641e..ba97de5 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -903,4 +903,15 @@
       "third_party:tiny_gltf_loader",
     ]
   }
+
+  group("dawn_samples") {
+    deps = [
+      ":CppHelloTriangle",
+      ":CHelloTriangle",
+      ":ComputeBoids",
+      ":Animometer",
+      ":CubeReflection",
+      ":glTFViewer",
+    ]
+  }
 }