Revert of Make chrome/BUILD.gn use symlink.gni rather than symlink.py directly...

Revert of Make chrome/BUILD.gn use symlink.gni rather than symlink.py directly (patchset #1 id:1 of https://codereview.chromium.org/2349603002/ )

Reason for revert:
Breaks BuildPackages due to GN error (https://bugs.chromium.org/p/chromium/issues/detail?id=647706).

BUG=647706

Original issue's description:
> Make chrome/BUILD.gn use symlink.gni rather than symlink.py directly
>
> Committed: https://crrev.com/ca5b9cba81bf335ce205cc06e094587b25c79758
> Cr-Commit-Position: refs/heads/master@{#419168}

TBR=dpranke@chromium.org,agrieve@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2344223002
Cr-Commit-Position: refs/heads/master@{#419190}

chrome/BUILD.gn

@@ -11,7 +11,6 @@ import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
 import("//build/config/win/console_app.gni")
 import("//build/config/win/manifest.gni")
-import("//build/symlink.gni")
 import("//chrome/chrome_repack_locales.gni")
 import("//chrome/common/features.gni")
 import("//chrome/version.gni")
@@ -774,9 +773,25 @@ if (is_win) {
   # root_out_dir, since copy_bundle_data copies the contents of the link
   # rather than the link itself.
   if (debug_devtools) {
-    symlink("devtools_debug_resources") {
-      source = "$root_out_dir/resources/inspector"
-      output = "$root_out_dir/$chrome_product_full_name.app/Contents/Versions/$chrome_version_full/$chrome_framework_name.framework/Resources/inspector"
+    action("devtools_debug_resources") {
+      _stamp = "$target_out_dir/run_${target_name}.stamp"
+
+      outputs = [
+        _stamp,
+      ]
+
+      script = "//build/symlink.py"
+      args = [
+        "-f",
+        "--touch",
+        rebase_path(_stamp, root_out_dir),
+
+        # Convert the symlink source and destination to an absolute paths, which
+        # makes symlinking easier (now pwd manipulation).
+        rebase_path("$root_out_dir/resources/inspector"),
+        rebase_path(
+            "$root_out_dir/$chrome_product_full_name.app/Contents/Versions/$chrome_version_full/$chrome_framework_name.framework/Resources/inspector"),
+      ]
 
       deps = [
         # Depend on :chrome_app to ensure that the bundle is produced before