Delete deprecated FecControllerFactoryInterface::CreateFecController variant

Bug: webrtc:10335
Change-Id: Id113133a9bf73830f16ac889e5e80633b5055279
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/333841
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#41491}
diff --git a/api/BUILD.gn b/api/BUILD.gn
index 6cec297..341b39c 100644
--- a/api/BUILD.gn
+++ b/api/BUILD.gn
@@ -890,7 +890,6 @@
 
   deps = [
     "../modules:module_fec_api",
-    "../rtc_base:checks",
     "environment",
     "video:video_frame_type",
   ]
diff --git a/api/fec_controller.h b/api/fec_controller.h
index 6f45ccb..5c2aa3b 100644
--- a/api/fec_controller.h
+++ b/api/fec_controller.h
@@ -17,7 +17,6 @@
 #include "api/environment/environment.h"
 #include "api/video/video_frame_type.h"
 #include "modules/include/module_fec_types.h"
-#include "rtc_base/checks.h"
 
 namespace webrtc {
 // TODO(yinwa): work in progress. API in class FecController should not be
@@ -91,21 +90,8 @@
  public:
   virtual ~FecControllerFactoryInterface() = default;
 
-  // TODO: bugs.webrtc.org/10335 - make pure virtual when implemented by derived
-  // classes.
   virtual std::unique_ptr<FecController> CreateFecController(
-      const Environment& env) {
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wdeprecated-declarations"
-    return CreateFecController();
-#pragma clang diagnostic pop
-  }
-
-  // TODO: bugs.webrtc.org/10335 - delete when implementation is removed from
-  // the derived classes.
-  [[deprecated]] virtual std::unique_ptr<FecController> CreateFecController() {
-    RTC_CHECK_NOTREACHED();
-  }
+      const Environment& env) = 0;
 };
 
 }  // namespace webrtc