--- a/dom/webidl/WebrtcGlobalInformation.webidl
+++ b/dom/webidl/WebrtcGlobalInformation.webidl
@@ -31,9 +31,11 @@ interface WebrtcGlobalInformation {
   // Notes:
   // - Setting a non-zero debug level turns on gathering of log for file output.
   // - Subsequently setting a zero debug level writes that log to disk.
 
   static attribute long debugLevel;
 
   // WebRTC AEC debugging enable
   static attribute boolean aecDebug;
+
+  static readonly attribute DOMString aecDebugLogDir;
 };

--- a/media/webrtc/signaling/src/common/browser_logging/WebRtcLog.cpp
+++ b/media/webrtc/signaling/src/common/browser_logging/WebRtcLog.cpp
@@ -252,45 +252,50 @@ void StopWebRtcLog()
   webrtc::Trace::SetTraceCallback(nullptr);
   webrtc::Trace::SetTraceFile(nullptr);
   if (sSink) {
     rtc::LogMessage::RemoveLogToStream(sSink);
     sSink = nullptr;
   }
 }
 
-void ConfigAecLog() {
+nsCString ConfigAecLog() {
+  nsCString aecLogDir;
   if (webrtc::Trace::aec_debug()) {
-    return;
+    return EmptyCString();
   }
-  nsCString aAECLogDir;
 #if defined(ANDROID)
-  aAECLogDir.Assign(default_tmp_dir);
+  aecLogDir.Assign(default_tmp_dir);
 #else
   nsCOMPtr<nsIFile> tempDir;
   nsresult rv = NS_GetSpecialDirectory(NS_OS_TEMP_DIR, getter_AddRefs(tempDir));
   if (NS_SUCCEEDED(rv)) {
-    tempDir->GetNativePath(aAECLogDir);
+    tempDir->GetNativePath(aecLogDir);
   }
 #endif
-  webrtc::Trace::set_aec_debug_filename(aAECLogDir.get());
+  webrtc::Trace::set_aec_debug_filename(aecLogDir.get());
+
+  return aecLogDir;
 }
 
-void StartAecLog()
+nsCString StartAecLog()
 {
+  nsCString aecLogDir;
   if (webrtc::Trace::aec_debug()) {
-    return;
+    return EmptyCString();
   }
   uint32_t trace_mask = 0;
   bool multi_log = false;
   nsAutoCString log_file;
 
   GetWebRtcLogPrefs(&trace_mask, log_file, &multi_log);
   CheckOverrides(&trace_mask, &log_file, &multi_log);
-  ConfigAecLog();
+  aecLogDir = ConfigAecLog();
 
   webrtc::Trace::set_aec_debug(true);
+
+  return aecLogDir;
 }
 
 void StopAecLog()
 {
   webrtc::Trace::set_aec_debug(false);
 }

--- a/media/webrtc/signaling/src/common/browser_logging/WebRtcLog.h
+++ b/media/webrtc/signaling/src/common/browser_logging/WebRtcLog.h
@@ -2,15 +2,15 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef WEBRTCLOG_H_
 #define WEBRTCLOG_H_
 
 #include "webrtc/common_types.h"
 
-void StartAecLog();
+nsCString StartAecLog();
 void StopAecLog();
 void StartWebRtcLog(uint32_t log_level = webrtc::kTraceDefault);
 void EnableWebRtcLog();
 void StopWebRtcLog();
 
 #endif

--- a/media/webrtc/signaling/src/peerconnection/WebrtcGlobalInformation.cpp
+++ b/media/webrtc/signaling/src/peerconnection/WebrtcGlobalInformation.cpp
@@ -661,16 +661,17 @@ WebrtcGlobalInformation::GetLogging(
     LogRequest::Delete(request->mRequestId);
   }
 
   aRv = rv;
 }
 
 static int32_t sLastSetLevel = 0;
 static bool sLastAECDebug = false;
+static Maybe<nsCString> sAecDebugLogDir;
 
 void
 WebrtcGlobalInformation::SetDebugLevel(const GlobalObject& aGlobal, int32_t aLevel)
 {
   if (aLevel) {
     StartWebRtcLog(webrtc::TraceLevel(aLevel));
   } else {
     StopWebRtcLog();
@@ -687,17 +688,17 @@ WebrtcGlobalInformation::DebugLevel(cons
 {
   return sLastSetLevel;
 }
 
 void
 WebrtcGlobalInformation::SetAecDebug(const GlobalObject& aGlobal, bool aEnable)
 {
   if (aEnable) {
-    StartAecLog();
+    sAecDebugLogDir.emplace(StartAecLog());
   } else {
     StopAecLog();
   }
 
   sLastAECDebug = aEnable;
 
   for (auto& cp : WebrtcContentParents::GetAll()){
     Unused << cp->SendSetAecLogging(aEnable);
@@ -705,16 +706,22 @@ WebrtcGlobalInformation::SetAecDebug(con
 }
 
 bool
 WebrtcGlobalInformation::AecDebug(const GlobalObject& aGlobal)
 {
   return sLastAECDebug;
 }
 
+void
+WebrtcGlobalInformation::GetAecDebugLogDir(const GlobalObject& aGlobal, nsAString& aDir)
+{
+  aDir = NS_ConvertASCIItoUTF16(sAecDebugLogDir.valueOr(EmptyCString()));
+}
+
 mozilla::ipc::IPCResult
 WebrtcGlobalParent::RecvGetStatsResult(const int& aRequestId,
                                        nsTArray<RTCStatsReportInternal>&& Stats)
 {
   MOZ_ASSERT(NS_IsMainThread());
   nsresult rv = NS_OK;
 
   StatsRequest* request = StatsRequest::Get(aRequestId);

--- a/media/webrtc/signaling/src/peerconnection/WebrtcGlobalInformation.h
+++ b/media/webrtc/signaling/src/peerconnection/WebrtcGlobalInformation.h
@@ -35,16 +35,17 @@ public:
 
   static void ClearLogging(const GlobalObject& aGlobal);
 
   static void SetDebugLevel(const GlobalObject& aGlobal, int32_t aLevel);
   static int32_t DebugLevel(const GlobalObject& aGlobal);
 
   static void SetAecDebug(const GlobalObject& aGlobal, bool aEnable);
   static bool AecDebug(const GlobalObject& aGlobal);
+  static void GetAecDebugLogDir(const GlobalObject& aGlobal, nsAString& aDir);
 
   static void StoreLongTermICEStatistics(PeerConnectionImpl& aPc);
 
 private:
   WebrtcGlobalInformation() = delete;
   WebrtcGlobalInformation(const WebrtcGlobalInformation& aOrig) = delete;
   WebrtcGlobalInformation& operator=(
     const WebrtcGlobalInformation& aRhs) = delete;

--- a/toolkit/content/aboutwebrtc/aboutWebrtc.js
+++ b/toolkit/content/aboutwebrtc/aboutWebrtc.js
@@ -257,17 +257,17 @@ function AecLogging() {
 }
 
 AecLogging.prototype = Object.create(Control.prototype);
 AecLogging.prototype.constructor = AecLogging;
 
 AecLogging.prototype.offState = function() {
   this._label = getString("aec_logging_off_state_label");
   try {
-    let file = Services.prefs.getCharPref("media.webrtc.debug.aec_log_dir");
+    let file = WebrtcGlobalInformation.aecDebugLogDir;
     this._message = formatString("aec_logging_off_state_msg", [file], 1);
   } catch (e) {
     this._message = null;
   }
 };
 
 AecLogging.prototype.onState = function() {
   this._label = getString("aec_logging_on_state_label");