Remove WebMediaPlayerMS from builds with WebRTC disabled.

When WebRTC is disabled, MediaStream and its supporting classes are not
compiled. In these builds, WebMediaPlayerMS is never usec.

Moreover, some spec-compliance improvements to WebMediaPlayerMS require
access to MediaStream methods. This causes non-WebRTC builds to break.

BUG=751054

Change-Id: Ia10362e082d88ba6a56a206eaf8126a4ca39ef81
Reviewed-on: https://chromium-review.googlesource.com/595727Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491321}

content/renderer/BUILD.gn

@@ -261,10 +261,6 @@ target(link_target_type, "renderer") {
     "media/video_capture_impl_manager.h",
     "media/web_media_element_source_utils.cc",
     "media/web_media_element_source_utils.h",
-    "media/webmediaplayer_ms.cc",
-    "media/webmediaplayer_ms.h",
-    "media/webmediaplayer_ms_compositor.cc",
-    "media/webmediaplayer_ms_compositor.h",
     "menu_item_builder.cc",
     "menu_item_builder.h",
     "message_delivery_policy.h",
@@ -660,6 +656,10 @@ target(link_target_type, "renderer") {
       "media/video_track_adapter.h",
       "media/webaudio_media_stream_source.cc",
       "media/webaudio_media_stream_source.h",
+      "media/webmediaplayer_ms.cc",
+      "media/webmediaplayer_ms.h",
+      "media/webmediaplayer_ms_compositor.cc",
+      "media/webmediaplayer_ms_compositor.h",
       "media/webrtc/media_stream_remote_video_source.cc",
       "media/webrtc/media_stream_remote_video_source.h",
       "media/webrtc/media_stream_track_metrics.cc",

content/test/BUILD.gn

@@ -1468,7 +1468,6 @@ test("content_unittests") {
     "../renderer/media/renderer_webaudiodevice_impl_unittest.cc",
     "../renderer/media/video_capture_impl_manager_unittest.cc",
     "../renderer/media/video_capture_impl_unittest.cc",
-    "../renderer/media/webmediaplayer_ms_unittest.cc",
     "../renderer/peripheral_content_heuristic_unittest.cc",
     "../renderer/presentation/presentation_connection_proxy_unittest.cc",
     "../renderer/presentation/presentation_dispatcher_unittest.cc",
@@ -1692,6 +1691,7 @@ test("content_unittests") {
       "../renderer/media/rtc_peer_connection_handler_unittest.cc",
       "../renderer/media/speech_recognition_audio_sink_unittest.cc",
       "../renderer/media/user_media_client_impl_unittest.cc",
+      "../renderer/media/webmediaplayer_ms_unittest.cc",
       "../renderer/media/webrtc/media_stream_remote_video_source_unittest.cc",
       "../renderer/media/webrtc/media_stream_track_metrics_unittest.cc",
       "../renderer/media/webrtc/media_stream_video_webrtc_sink_unittest.cc",