Reland "Use backticks not vertical bars to denote variables in comments for /pc"

Original change's description:
> Revert "Use backticks not vertical bars to denote variables in comments for /pc"
>
> This reverts commit 37ee0f5e594dd772ec6d620b5e5ea8a751b684f0.
>
> Reason for revert: Revert in order to be able to revert https://webrtc-review.googlesource.com/c/src/+/225642
>
> Original change's description:
> > Use backticks not vertical bars to denote variables in comments for /pc
> >
> > Bug: webrtc:12338
> > Change-Id: I88cf10afa5fc810b95d2a585ab2e895dcc163b63
> > Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/226953
> > Reviewed-by: Harald Alvestrand <hta@webrtc.org>
> > Commit-Queue: Artem Titov <titovartem@webrtc.org>
> > Cr-Commit-Position: refs/heads/master@{#34575}
>
> TBR=hta@webrtc.org,titovartem@webrtc.org,webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com
>
> Change-Id: I5eddd3a14e1f664bf831e5c294fbc4de5f6a88af
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: webrtc:12338
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227082
> Reviewed-by: Björn Terelius <terelius@webrtc.org>
> Commit-Queue: Björn Terelius <terelius@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#34577}

Bug: webrtc:12338
Change-Id: I96bd229b73613c162d11d75fa4f5934e1b4295c7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227087
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34611}
diff --git a/pc/webrtc_sdp.h b/pc/webrtc_sdp.h
index aa3317f..6d6980a 100644
--- a/pc/webrtc_sdp.h
+++ b/pc/webrtc_sdp.h
@@ -94,18 +94,18 @@
                                         cricket::Candidate* candidate,
                                         SdpParseError* error);
 
-// Parses |message| according to the grammar defined in RFC 5245, Section 15.1
-// and, if successful, stores the result in |candidate| and returns true.
-// If unsuccessful, returns false and stores error information in |error| if
-// |error| is not null.
-// If |is_raw| is false, |message| is expected to be prefixed with "a=".
-// If |is_raw| is true, no prefix is expected in |messaage|.
+// Parses `message` according to the grammar defined in RFC 5245, Section 15.1
+// and, if successful, stores the result in `candidate` and returns true.
+// If unsuccessful, returns false and stores error information in `error` if
+// `error` is not null.
+// If `is_raw` is false, `message` is expected to be prefixed with "a=".
+// If `is_raw` is true, no prefix is expected in `messaage`.
 RTC_EXPORT bool ParseCandidate(const std::string& message,
                                cricket::Candidate* candidate,
                                SdpParseError* error,
                                bool is_raw);
 
-// Generates an FMTP line based on |parameters|. Please note that some
+// Generates an FMTP line based on `parameters`. Please note that some
 // parameters are not considered to be part of the FMTP line, see the function
 // IsFmtpParam(). Returns true if the set of FMTP parameters is nonempty, false
 // otherwise.