Revert of Remove deprecated CodecType methods. (patchset #1 id:1 of https://codereview.webrtc.org/3009583002/ )

Reason for revert:
It breaks chromium FYI bots.

E.g.: https://build.chromium.org/p/chromium.webrtc.fyi/builders/Win%20Builder/builds/11615

Original issue's description:
> Remove deprecated CodecType methods.
>
> These are no longer needed as all clients have been updated to use the
> new methods that always return a value.
>
> BUG=None
>
> Review-Url: https://codereview.webrtc.org/3009583002
> Cr-Commit-Position: refs/heads/master@{#19559}
> Committed: https://chromium.googlesource.com/external/webrtc/+/1a92d0de49779567241e97e50cb69d51257adcce

TBR=magjed@webrtc.org,tommi@webrtc.org,kthelgason@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=None

Review-Url: https://codereview.webrtc.org/3010553002
Cr-Commit-Position: refs/heads/master@{#19563}
diff --git a/webrtc/common_types.cc b/webrtc/common_types.cc
index 6cf7304..82307ce 100644
--- a/webrtc/common_types.cc
+++ b/webrtc/common_types.cc
@@ -168,6 +168,16 @@
   return kVideoCodecGeneric;
 }
 
+// TODO(kthelgason): Remove these methods once upstream projects
+// have been updated.
+rtc::Optional<const char*> CodecTypeToPayloadName(VideoCodecType type) {
+  return rtc::Optional<const char*>(CodecTypeToPayloadString(type));
+}
+
+rtc::Optional<VideoCodecType> PayloadNameToCodecType(const std::string& name) {
+  return rtc::Optional<VideoCodecType>(PayloadStringToCodecType(name));
+}
+
 const uint32_t BitrateAllocation::kMaxBitrateBps =
     std::numeric_limits<uint32_t>::max();
 
diff --git a/webrtc/common_types.h b/webrtc/common_types.h
index fcb4381..ac5c2e2 100644
--- a/webrtc/common_types.h
+++ b/webrtc/common_types.h
@@ -553,6 +553,10 @@
 // Translates from name of codec to codec type and vice versa.
 const char* CodecTypeToPayloadString(VideoCodecType type);
 VideoCodecType PayloadStringToCodecType(const std::string& name);
+// TODO(kthelgason): Remove these methods once upstream projects
+// have been updated.
+rtc::Optional<const char*> CodecTypeToPayloadName(VideoCodecType type);
+rtc::Optional<VideoCodecType> PayloadNameToCodecType(const std::string& name);
 
 union VideoCodecUnion {
   VideoCodecVP8 VP8;