Remove obsolete win_pdf_metafile_for_printing GN flag.

Review URL: https://codereview.chromium.org/1552673002

Cr-Original-Commit-Position: refs/heads/master@{#367364}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: f5180a8f93deaaeb1032bf9a89a7f00bdc4c31d7
diff --git a/tools/gn/docs/cookbook.md b/tools/gn/docs/cookbook.md
index 7a69737..3f9f1f4 100644
--- a/tools/gn/docs/cookbook.md
+++ b/tools/gn/docs/cookbook.md
@@ -257,7 +257,6 @@
 | `use_udev` (0/1)                        | `use_udev` (true/false)                        | `//build/config/features.gni` |
 | `use_x11` (0/1)                         | `use_x11` (true/false)                         | `//build/config/ui.gni`       |
 | `use_xi2_mt` (0/1)                      | `use_xi2_mt` (true/false)                      | `//build/config/ui.gni`       |
-| `win_pdf_metafile_for_printing` (0/1)   | `win_pdf_metafile_for_printing` (true/false)   | `//build/config/features.gni` |
 | `win_use_allocator_shim` (0/1)          |                                                | (See "Allocator" below)       |
 
 ### Common target conversion