Fix GN visibility checks when building with chromium.

Standalone pdfium doesn't have a //base/BUILD.gn upon which to depend,
so it must depend on the partition_allocator sub-directory targets.
These violate GN constraints, however, when PDFium is built in a
non-standalone manner and //base is available.

This is currently blocking a roll of PDFium into chromium.

Bug: pdfium:2038
Change-Id: Ib2c6a84876036902d6873dedfc18e030c5aa7c6c
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/107711
Reviewed-by: K. Moon <kmoon@chromium.org>
Reviewed-by: Nigi <nigi@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fxcrt/BUILD.gn b/core/fxcrt/BUILD.gn
index 6837b1a..b6dc8de 100644
--- a/core/fxcrt/BUILD.gn
+++ b/core/fxcrt/BUILD.gn
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build_overrides/build.gni")
 import("../../pdfium.gni")
 import("../../testing/test.gni")
 
@@ -9,12 +10,15 @@
   sources = [ "unowned_ptr.h" ]
   deps = [ "../../third_party:pdfium_compiler_specific" ]
   configs += [ "../../:pdfium_strict_config" ]
-
   if (pdf_use_partition_alloc) {
-    deps += [
-      "//base/allocator/partition_allocator:partition_alloc_buildflags",
-      "//base/allocator/partition_allocator:raw_ptr",
-    ]
+    if (build_with_chromium) {
+      deps += [ "//base" ]
+    } else {
+      deps += [
+        "//base/allocator/partition_allocator:partition_alloc_buildflags",
+        "//base/allocator/partition_allocator:raw_ptr",
+      ]
+    }
   }
 }
 
@@ -145,11 +149,15 @@
   ]
   if (pdf_use_partition_alloc) {
     sources += [ "fx_memory_pa.cpp" ]
-    deps += [
-      "//base/allocator/partition_allocator:partition_alloc",
-      "//base/allocator/partition_allocator:partition_alloc_buildflags",
-      "//base/allocator/partition_allocator:raw_ptr",
-    ]
+    if (build_with_chromium) {
+      deps += [ "//base" ]
+    } else {
+      deps += [
+        "//base/allocator/partition_allocator:partition_alloc",
+        "//base/allocator/partition_allocator:partition_alloc_buildflags",
+        "//base/allocator/partition_allocator:raw_ptr",
+      ]
+    }
   } else {
     sources += [ "fx_memory_malloc.cpp" ]
   }