🐍 Fix GN deps needed by third_party/WebKit/Tools/Scripts/run-webkit-tests

tools/imagediff/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-executable("imagediff") {
-  output_name = "image_diff"  # Different than dir nam for historical reasons.
-  sources = [
-    "image_diff.cc",
-    "image_diff_png.cc",
-    "image_diff_png.h",
-  ]
+import("//build/symlink.gni")
 
-  configs += [ "//build/config/compiler:wexit_time_destructors" ]
+if (current_toolchain == host_toolchain) {
+  executable("imagediff") {
+    output_name = "image_diff"  # Different than dir nam for historical reasons.
+    sources = [
+      "image_diff.cc",
+      "image_diff_png.cc",
+      "image_diff_png.h",
+    ]
 
-  deps = [
-    "//base",
-    "//build/config/sanitizers:deps",
-    "//third_party/libpng",
-    "//third_party/zlib",
-  ]
+    configs += [ "//build/config/compiler:wexit_time_destructors" ]
+
+    deps = [
+      "//base",
+      "//build/config/sanitizers:deps",
+      "//third_party/libpng",
+      "//third_party/zlib",
+    ]
+  }
+} else {
+  # Aliases for compatibility with GYP.
+  binary_symlink("imagediff") {
+    binary_label = ":$target_name($host_toolchain)"
+    binary_output_name = "image_diff"
+  }
 }