Move direct use of VideoCapturer::VideoAdapter to VideoSinkWants.

webrtc/media/base/videocapturer.cc

Index: webrtc/media/base/videocapturer.cc
diff --git a/webrtc/media/base/videocapturer.cc b/webrtc/media/base/videocapturer.cc
index 2d6a15e544046e3ee768ae7b39e4c8a18251cca0..511be8eda948ce23fee8f962764f13e59137f202 100644
--- a/webrtc/media/base/videocapturer.cc
+++ b/webrtc/media/base/videocapturer.cc
@@ -334,6 +334,15 @@ void VideoCapturer::OnSinkWantsChanged(const rtc::VideoSinkWants& wants) {
   if (frame_factory_) {
     frame_factory_->SetApplyRotation(apply_rotation_);
   }
+
+  // Do not adapt resolution for screen content as this will likely result in
+  // blurry and unreadable text.
+  if (wants.resolution != rtc::VideoSinkWants::Resolution::KEEP &&
+      !IsScreencast() && video_adapter()) {
+    video_adapter()->OnCpuResolutionRequest(
+        wants.resolution == rtc::VideoSinkWants::Resolution::DOWN ?
+        CoordinatedVideoAdapter::DOWNGRADE : CoordinatedVideoAdapter::UPGRADE);
+  }
 }
 
 void VideoCapturer::OnFrameCaptured(VideoCapturer*,