XFA: Sync samples/ build files with master.

This makes pdfium_test always link with the bundled freetype, which will
fix many failing corpus tests.

This merges snippets of 34bb6c58fe60206a08dc0a1f37b7cfe83e8c762c

R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1423063006 .
diff --git a/samples/BUILD.gn b/samples/BUILD.gn
index 2039d2f..6cb76e9 100644
--- a/samples/BUILD.gn
+++ b/samples/BUILD.gn
@@ -8,6 +8,7 @@
   testonly = true
   deps = [
     ":pdfium_test",
+    ":pdfium_diff",
   ]
 }
 
@@ -17,6 +18,7 @@
     "PNGPREFIX_H",
     "PNG_USE_READ_MACROS",
   ]
+  include_dirs = [ ".." ]
   if (pdf_enable_v8) {
     defines += [ "PDF_ENABLE_V8", ]
   }
@@ -34,11 +36,14 @@
   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",
   ]
   if (pdf_enable_v8) {
-    deps += [
-      "//v8:v8_libplatform",
-    ]
+    deps += [ "//v8:v8_libplatform" ]
     include_dirs = [
       "//v8",
       "//v8/include",
@@ -57,5 +62,9 @@
   deps = [
     "//third_party/pdfium",
   ]
-  configs += [ ":pdfium_samples_config" ]
+  configs -= [ "//build/config/compiler:chromium_code" ]
+  configs += [
+    ":pdfium_samples_config",
+    "//build/config/compiler:no_chromium_code",
+  ]
 }