electron/patches/chromium/resource_file_conflict.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jeremy Apthorp <nornagon@nornagon.net>
Date: Thu, 20 Sep 2018 17:48:59 -0700
Subject: resource_file_conflict.patch

Resolve conflict between //chrome's .pak files and //electron's. The paths
that chrome code hardcodes require that we generate resources at these
paths, but GN throws errors if there are multiple targets that generate the
same files.

This is due to the hardcoded names here:
https://chromium.googlesource.com/chromium/src/+/69.0.3497.106/ui/base/resource/resource_bundle.cc#780
and here:
https://chromium.googlesource.com/chromium/src/+/69.0.3497.106/ui/base/resource/resource_bundle_mac.mm#50

This isn't needed on Mac because resource files are copied into the app bundle,
and are built in `$root_out_dir/electron_repack` (while Chromium's resources
target `$root_out_dir/repack`), but on Windows and Linux, the resource files go
directly in `$root_out_dir`, and so they conflict.

We don't actually ever generate Chromium's resource paks, but without this
patch, GN refuses to generate the ninja files:

   ERROR at //tools/grit/repack.gni:35:3: Duplicate output file.
     action(_repack_target_name) {
     ^----------------------------
   Two or more targets generate the same output:
     chrome_100_percent.pak

   This is can often be fixed by changing one of the target names, or by
   setting an output_name on one of them.

   Collisions:
     //chrome:packed_resources_100_percent
     //electron:packed_resources_100_percent

   See //tools/grit/repack.gni:35:3: Collision.
     action(_repack_target_name) {
     ^----------------------------

Some alternatives to this patch:

1. Refactor upstream in such a way that the "chrome" pak names were
   configurable, for instance by adding a method to ResourceBundle::Delegate that
   LoadChromeResources would check.
2. Pass a Delegate that overrides `GetPathForResourcePack`, check for the
   `chrome_{100,200}_percent.pak` filenames, and rewrite them to
   `electron_{100,200}_percent.pak`.
3. Initialize the resource bundle with DO_NOT_LOAD_COMMON_RESOURCES and load
   the paks ourselves.

None of these options seems like a substantial maintainability win over this patch to me (@nornagon).

diff --git a/chrome/BUILD.gn b/chrome/BUILD.gn
index d078afa65f08c847683897fba1952b098003f06b..268344419ba130700cf75fd8780678ad087a2970 100644
--- a/chrome/BUILD.gn
+++ b/chrome/BUILD.gn
@@ -1423,7 +1423,7 @@ if (is_chrome_branded && !is_android) {
   }
 }
 
-if (!is_android) {
+if (!is_android && !is_electron_build) {
   chrome_paks("packed_resources") {
     if (is_mac) {
       output_dir = "$root_gen_dir/repack"
@@ -1443,6 +1443,12 @@ if (!is_android) {
   }
 }
 
+if (is_electron_build) {
+  group("packed_resources") {
+    public_deps = [ "//electron:packed_resources" ]
+  }
+}
+
 repack("browser_tests_pak") {
   sources = [ "$root_gen_dir/chrome/webui_test_resources.pak" ]
   output = "$root_out_dir/browser_tests.pak"