Remove redundant source files in //ios/web/public/BUILD.gn.

This CL removes the temporary source file items in
//ios/web/public/BUILD.gn that were kept to avoid brekaing ios_internal.
Since the dependency chain in ios_internal has been updated, these items
can be removed now.

Bug: 942244,956511
Change-Id: I76153ec5e2f5407299e2c14ec51de9a429619e5d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1634859Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: Yi Su <mrsuyi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664248}

ios/web/public/BUILD.gn

@@ -34,8 +34,6 @@ source_set("public") {
     "navigation_item.h",
     "navigation_manager.h",
     "reload_type.h",
-    "security/cert_policy.h",
-    "security/certificate_policy_cache.h",
     "service_manager_connection.h",
     "url_data_source_ios.h",
     "url_scheme_util.h",

ios/web/session/BUILD.gn

@@ -7,6 +7,7 @@ source_set("session") {
   deps = [
     "//base",
     "//ios/web/public",
+    "//ios/web/public/security",
     "//ios/web/public/session",
     "//net",
   ]
@@ -25,6 +26,7 @@ source_set("unittests") {
   testonly = true
   deps = [
     "//ios/web/public",
+    "//ios/web/public/security",
     "//ios/web/public/session",
     "//ios/web/public/test",
     "//ios/web/public/test/fakes",