Rewrite videoprocessor integrationtest to use public fixture.

This CL creates a test fixture for the videoprocessor integration tests
and exposes it as part of the public API. It also rewrites the current
versions of the tests to build on this new paradigm. The motivation for
this is to easily allow projects that build on top of webrtc to add
integration-level tests for their own custom codec implementations in a
way that does not link them too tightly to the internal implementations
of said tests.

Bug: None
Change-Id: I7cf9f29322a6934b3cfc32da02ea7dfa5858c2b2
Reviewed-on: https://webrtc-review.googlesource.com/72481
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23118}
diff --git a/api/BUILD.gn b/api/BUILD.gn
index bdff109..d5da182 100644
--- a/api/BUILD.gn
+++ b/api/BUILD.gn
@@ -375,6 +375,38 @@
     }
   }
 
+  rtc_source_set("videocodec_test_fixture_api") {
+    visibility = [ "*" ]
+    testonly = true
+    sources = [
+      "test/videocodec_test_fixture.h",
+    ]
+    deps = [
+      "../modules/video_coding:video_codecs_test_framework",
+      "video_codecs:video_codecs_api",
+    ]
+  }
+
+  rtc_source_set("create_videocodec_test_fixture_api") {
+    visibility = [ "*" ]
+    testonly = true
+    sources = [
+      "test/create_videocodec_test_fixture.cc",
+      "test/create_videocodec_test_fixture.h",
+    ]
+    deps = [
+      ":videocodec_test_fixture_api",
+      "../modules/video_coding:video_codecs_test_framework",
+      "../modules/video_coding:videocodec_test_impl",
+      "../rtc_base:rtc_base_approved",
+      "video_codecs:video_codecs_api",
+    ]
+    if (!build_with_chromium && is_clang) {
+      # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
+      suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
+    }
+  }
+
   rtc_source_set("mock_audio_mixer") {
     testonly = true
     sources = [