Fixing nested namespace and thread checker macros in //remoting/protocol

Since working in this directory I've noticed that the presubmits will
'fail' if you modify a file with a nested namespace with the suggestion
that you should use the new style (namespace1::namespace2). I'd like to
be able to make quick modifications when needed without also dealing
with namespace formatting so I decided to fix this in a separate CL.

Along the same lines, I noticed that we aren't using the suggested
ThreadChecker macros consistently so I fixed that as well.

This CL also contains a small number of comment reflows and simple
modernization changes. I didn't do this exhaustively but there are a
handful which I noticed while fixing the other problems

No functional changes are expected as a result of these changes.

Change-Id: Ib99429b79fc9a3c55596602e279be8487866660c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3852429
Commit-Queue: Joe Downing <[email protected]>
Reviewed-by: Lambros Lambrou <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1039396}
diff --git a/remoting/protocol/webrtc_frame_scheduler.h b/remoting/protocol/webrtc_frame_scheduler.h
index 7f0e737..7d3a8f3 100644
--- a/remoting/protocol/webrtc_frame_scheduler.h
+++ b/remoting/protocol/webrtc_frame_scheduler.h
@@ -12,8 +12,7 @@
 class DesktopFrame;
 }  // namespace webrtc
 
-namespace remoting {
-namespace protocol {
+namespace remoting::protocol {
 
 // An abstract interface for frame schedulers, which are responsible for
 // scheduling when video frames are captured and for defining encoding
@@ -30,16 +29,15 @@
   // Pause and resumes the scheduler.
   virtual void Pause(bool pause) = 0;
 
-  // Called after |frame| has been captured. |frame| may be set to nullptr
-  // if the capture request failed.
+  // Called after |frame| has been captured. |frame| may be set to nullptr if
+  // the capture request failed.
   virtual void OnFrameCaptured(const webrtc::DesktopFrame* frame) = 0;
 
-  // Called when WebRTC requests the VideoTrackSource to provide frames
-  // at a maximum framerate.
+  // Called when WebRTC requests the VideoTrackSource to provide frames at a
+  // maximum framerate.
   virtual void SetMaxFramerateFps(int max_framerate_fps) = 0;
 };
 
-}  // namespace protocol
-}  // namespace remoting
+}  // namespace remoting::protocol
 
 #endif  // REMOTING_PROTOCOL_WEBRTC_FRAME_SCHEDULER_H_