[viz, capture] Add debug logging to FrameSinkVideoCapturer

The logging messages are propagated along the pipeline until they reach
browser process, which already knows how to forward them to the WebRTC
log in a renderer.

Added callback from CaptureOracle to FrameSinkVideoCapturer to forward
log messages.

All the debug logging is behind the chrome feature so it can be enabled
for a fraction of users.

Bug: webrtc:11461
Change-Id: I0005950670e1efb96b86857f1494894e1253f339
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2126986
Reviewed-by: Guido Urdaneta <[email protected]>
Reviewed-by: Dana Fried <[email protected]>
Reviewed-by: kylechar <[email protected]>
Reviewed-by: Andrey Kosyakov <[email protected]>
Reviewed-by: Martin Barbella <[email protected]>
Reviewed-by: Dmitry Gozman <[email protected]>
Commit-Queue: Guido Urdaneta <[email protected]>
Auto-Submit: Ilya Nikolaevskiy <[email protected]>
Cr-Commit-Position: refs/heads/master@{#756223}
diff --git a/content/browser/devtools/devtools_video_consumer.h b/content/browser/devtools/devtools_video_consumer.h
index aa86ec8..fe4ab8181 100644
--- a/content/browser/devtools/devtools_video_consumer.h
+++ b/content/browser/devtools/devtools_video_consumer.h
@@ -70,6 +70,7 @@
       mojo::PendingRemote<viz::mojom::FrameSinkVideoConsumerFrameCallbacks>
           callbacks) override;
   void OnStopped() override;
+  void OnLog(const std::string& /*message*/) override {}
 
   // Default min frame size is 1x1, as otherwise, nothing would be captured.
   static constexpr gfx::Size kDefaultMinFrameSize = gfx::Size(1, 1);