Standalone GN build.

samples/BUILD.gn

Index: samples/BUILD.gn
diff --git a/samples/BUILD.gn b/samples/BUILD.gn
index 5e300158c9a07312d4b52c1cd51866ea9f59501a..83c510d7c86887c5f29ebb1284c69d827cf5ec40 100644
--- a/samples/BUILD.gn
+++ b/samples/BUILD.gn
@@ -39,14 +39,14 @@ executable("pdfium_test") {
     "pdfium_test.cc",
   ]
   deps = [
+    "../:pdfium",
+    "../:test_support",
     "//build/config/sanitizers:deps",
-    "//third_party/pdfium:pdfium",
-    "//third_party/pdfium:test_support",
 
     # Regardless of whether the library ships against system freetype,
     # always link this binary against the bundled one for consistency
     # of results across platforms.
-    "//third_party/pdfium/third_party:fx_freetype",
+    "../third_party:fx_freetype",
   ]
   if (!pdf_enable_xfa) {
     deps += [ "../third_party:fx_lpng" ]
@@ -73,8 +73,8 @@ executable("pdfium_diff") {
     "image_diff_png.h",
   ]
   deps = [
+    "../:pdfium",
     "//build/config/sanitizers:deps",
-    "//third_party/pdfium",
   ]
   if (!pdf_enable_xfa) {
     deps += [ "../third_party:fx_lpng" ]