Renames test::VideoCapturer to TestVideoCapturer.

Bug: webrtc:9620
Change-Id: Ia9afbc2d4f0448f9479516baa741d925a0aca5ac
Reviewed-on: https://webrtc-review.googlesource.com/93760
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24346}

test/BUILD.gn

diff --git a/test/BUILD.gn b/test/BUILD.gn
index 6a37622..ac56bc6 100644
--- a/test/BUILD.gn
+++ b/test/BUILD.gn
@@ -44,10 +44,10 @@
     "frame_generator_capturer.h",
     "frame_utils.cc",
     "frame_utils.h",
+    "test_video_capturer.cc",
+    "test_video_capturer.h",
     "vcm_capturer.cc",
     "vcm_capturer.h",
-    "video_capturer.cc",
-    "video_capturer.h",
     "video_codec_settings.h",
   ]