[ios] Add hooks for cpe internal entitlements

Bug: 1049638
Change-Id: I623e7655777a023df89299ef4211e891d0b69cfd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2091528Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Commit-Queue: David Jean <djean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748149}

ios/build/chrome_build.gni

@@ -43,6 +43,9 @@ declare_args() {
   # Overridable list of dependencies that are forbidden for
   # //ios/chrome/app:chrome target.
   ios_chrome_extra_assert_no_deps = []
+
+  # List of plist templates to merge when generating chrome cpe entitlements.
+  ios_chrome_cpe_entitlements_additions = []
 }
 
 # Configure whether breakpad support is enabled.

ios/chrome/credential_provider_extension/BUILD.gn

@@ -33,6 +33,9 @@ compile_entitlements("entitlements") {
   entitlements_templates = [
     "entitlements/external/credential_provider_extension.appex.entitlements",
   ]
+  if (ios_chrome_cpe_entitlements_additions != []) {
+    entitlements_templates += ios_chrome_cpe_entitlements_additions
+  }
 }
 
 ios_appex_bundle("credential_provider_extension") {