Some cleanups to observatory BUILD.gn

runtime/observatory/BUILD.gn

Index: runtime/observatory/BUILD.gn
diff --git a/runtime/observatory/BUILD.gn b/runtime/observatory/BUILD.gn
index faa5e001706bfc136f7611773c46489431a93d7e..a4a76ee5a630a0dc8598025a242135193625ff98 100644
--- a/runtime/observatory/BUILD.gn
+++ b/runtime/observatory/BUILD.gn
@@ -10,7 +10,7 @@ declare_args() {
 
   # Specify the path to a host compatible version of pub.
   # This is used to compile the Observatory frontend sources.
-  dart_host_pub_exe = rebase_path("$dart_host_sdk/pub")
+  dart_host_pub_exe = rebase_path("$dart_host_sdk/bin/pub")
 }
 
 # Helper build rules for packaging the Dart observatory resources.
@@ -44,7 +44,7 @@ action("write_observatory_pubspec_yaml") {
   args = [
     "--silent=True",
     "--pub-executable",
-    rebase_path("//third_party/dart-sdk/dart-sdk/bin/pub"),
+    dart_host_pub_exe,
     "--directory",
     rebase_path("$root_gen_dir/observatory_copy/dart/runtime/observatory/"),
     "--command",
@@ -76,7 +76,7 @@ action("copy_observatory_deps") {
   args = [
     "--silent=True",
     "--pub-executable",
-    rebase_path("//third_party/dart-sdk/dart-sdk/bin/pub"),
+    dart_host_pub_exe,
     "--directory",
     rebase_path("$root_gen_dir/observatory_copy/dart/runtime/observatory/"),
     "--command",
@@ -109,7 +109,7 @@ action("pub_build_observatory") {
   args = [
     "--silent=True",
     "--pub-executable",
-    rebase_path("//third_party/dart-sdk/dart-sdk/bin/pub"),
+    dart_host_pub_exe,
     "--directory",
     rebase_path("$root_gen_dir/observatory_copy/dart/runtime/observatory/"),
     "--command",
@@ -139,7 +139,7 @@ action("deploy_observatory") {
   args = [
     "--silent=True",
     "--pub-executable",
-    rebase_path("//third_party/dart-sdk/dart-sdk/bin/pub"),
+    dart_host_pub_exe,
     "--directory",
     rebase_path("$root_out_dir/observatory"),
     "--command",
@@ -180,4 +180,14 @@ action("archive_observatory") {
     "$root_gen_dir/observatory/observatory_archive.cc",
     "$root_gen_dir/observatory/observatory_archive.tar",
   ]
-}
+}
+
+source_set("embedded_observatory_archive") {
+  deps = [
+    ":archive_observatory",
+  ]
+
+  sources = [
+    rebase_path("$root_gen_dir/observatory/observatory_archive.cc"),
+  ]
+}