Export symbols needed by the Chromium component build (part 8).

This CL uses RTC_EXPORT (defined in rtc_base/system/rtc_export.h)
to mark WebRTC symbols as visible from a shared library, this doesn't
mean these symbols are part of the public API (please continue to refer
to [1] for info about what is considered public WebRTC API).

[1] - https://webrtc.googlesource.com/src/+/HEAD/native-api.md

Bug: webrtc:9419
Change-Id: Ib2c29054b2ae008f5291bd3b762a504b18534326
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/130513
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27410}
diff --git a/pc/webrtc_sdp.h b/pc/webrtc_sdp.h
index 3ba5c7f..94008a0 100644
--- a/pc/webrtc_sdp.h
+++ b/pc/webrtc_sdp.h
@@ -67,9 +67,9 @@
 // candidates - The JsepIceCandidate from the SDP string.
 // error - The detail error information when parsing fails.
 // return - true on success, false on failure.
-bool SdpDeserializeCandidate(const std::string& message,
-                             JsepIceCandidate* candidate,
-                             SdpParseError* error);
+RTC_EXPORT bool SdpDeserializeCandidate(const std::string& message,
+                                        JsepIceCandidate* candidate,
+                                        SdpParseError* error);
 
 // Deserializes the passed in SDP string to a cricket Candidate.
 // The first line must be a=candidate line and only the first line will be