Introduce SubframeNavigationFilteringThrottle

components/subresource_filter/content/browser/BUILD.gn

Index: components/subresource_filter/content/browser/BUILD.gn
diff --git a/components/subresource_filter/content/browser/BUILD.gn b/components/subresource_filter/content/browser/BUILD.gn
index cac67013f1eda687f00b0a47549de5a93d038544..f88727468eaecc9401dac0e6786ad97e9fb83677 100644
--- a/components/subresource_filter/content/browser/BUILD.gn
+++ b/components/subresource_filter/content/browser/BUILD.gn
@@ -12,6 +12,8 @@ static_library("browser") {
     "content_subresource_filter_driver.h",
     "content_subresource_filter_driver_factory.cc",
     "content_subresource_filter_driver_factory.h",
+    "subframe_filtering_navigation_throttle.cc",
+    "subframe_filtering_navigation_throttle.h",
     "verified_ruleset_dealer.cc",
     "verified_ruleset_dealer.h",
   ]
@@ -37,6 +39,7 @@ source_set("unit_tests") {
     "async_document_subresource_filter_unittest.cc",
     "content_ruleset_service_delegate_unittest.cc",
     "content_subresource_filter_driver_factory_unittest.cc",
+    "subframe_filtering_navigation_throttle_unittest.cc",
     "verified_ruleset_dealer_unittest.cc",
   ]
   deps = [