Add plumbing for key pinning over component updater

This CL adds the required plumbing for updating the
static pins list using component updater, including
updating pki_metadata_component_installer so it
parses the pins list, and all plumbing up to the
network service.

This CL does not implement actual enforcement using the component
provided list, that will be added in a follow up.

Bug: 1286121
Change-Id: Ib54c2005db9f61f768b7729b9007ef35145e3801
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3379445
Reviewed-by: David Benjamin <[email protected]>
Reviewed-by: Clark DuVall <[email protected]>
Reviewed-by: Joshua Pawlicki <[email protected]>
Reviewed-by: Mustafa Emre Acer <[email protected]>
Auto-Submit: Carlos IL <[email protected]>
Reviewed-by: Colin Blundell <[email protected]>
Commit-Queue: Carlos IL <[email protected]>
Cr-Commit-Position: refs/heads/main@{#981663}
diff --git a/chrome/browser/net/BUILD.gn b/chrome/browser/net/BUILD.gn
index 895aa8bb9..fb0d68d7 100644
--- a/chrome/browser/net/BUILD.gn
+++ b/chrome/browser/net/BUILD.gn
@@ -12,6 +12,13 @@
   sources = [ "probe_message.proto" ]
 }
 
+proto_library("key_pinning_proto") {
+  sources = [
+    "key_pinning.proto",
+    "kp_timestamp.proto",
+  ]
+}
+
 if (is_android) {
   java_cpp_enum("secure_dns_management_mode_generated_enum") {
     sources = [ "secure_dns_config.h" ]