diff --git a/webrtc/media/base/fakemediaengine.h b/webrtc/media/base/fakemediaengine.h
index 1e1ef6c9db..b9be39bdcf 100644
--- a/webrtc/media/base/fakemediaengine.h
+++ b/webrtc/media/base/fakemediaengine.h
@@ -716,6 +716,16 @@ class FakeBaseEngine {
     capabilities_.header_extensions = extensions;
   }
 
+  void set_rtp_header_extensions(
+      const std::vector<cricket::RtpHeaderExtension>& extensions) {
+    for (const cricket::RtpHeaderExtension& ext : extensions) {
+      RtpExtension webrtc_ext;
+      webrtc_ext.uri = ext.uri;
+      webrtc_ext.id = ext.id;
+      capabilities_.header_extensions.push_back(webrtc_ext);
+    }
+  }
+
  protected:
   // Flag used by optionsmessagehandler_unittest for checking whether any
   // relevant setting has been updated.
@@ -861,6 +871,15 @@ class FakeMediaEngine :
     video_.set_rtp_header_extensions(extensions);
   }
 
+  void SetAudioRtpHeaderExtensions(
+      const std::vector<cricket::RtpHeaderExtension>& extensions) {
+    voice_.set_rtp_header_extensions(extensions);
+  }
+  void SetVideoRtpHeaderExtensions(
+      const std::vector<cricket::RtpHeaderExtension>& extensions) {
+    video_.set_rtp_header_extensions(extensions);
+  }
+
   FakeVoiceMediaChannel* GetVoiceChannel(size_t index) {
     return voice_.GetChannel(index);
   }
diff --git a/webrtc/media/base/mediachannel.h b/webrtc/media/base/mediachannel.h
index 61e450d4e1..ee431537b9 100644
--- a/webrtc/media/base/mediachannel.h
+++ b/webrtc/media/base/mediachannel.h
@@ -320,6 +320,24 @@ struct VideoOptions {
   }
 };
 
+// TODO(isheriff): Remove this once client usage is fixed to use RtpExtension.
+struct RtpHeaderExtension {
+  RtpHeaderExtension() : id(0) {}
+  RtpHeaderExtension(const std::string& uri, int id) : uri(uri), id(id) {}
+
+  std::string ToString() const {
+    std::ostringstream ost;
+    ost << "{";
+    ost << "uri: " << uri;
+    ost << ", id: " << id;
+    ost << "}";
+    return ost.str();
+  }
+
+  std::string uri;
+  int id;
+};
+
 class MediaChannel : public sigslot::has_slots<> {
  public:
   class NetworkInterface {
diff --git a/webrtc/pc/mediasession.h b/webrtc/pc/mediasession.h
index 0a04bcf93f..272775e6b5 100644
--- a/webrtc/pc/mediasession.h
+++ b/webrtc/pc/mediasession.h
@@ -209,6 +209,13 @@ class MediaContentDescription : public ContentDescription {
     rtp_header_extensions_.push_back(ext);
     rtp_header_extensions_set_ = true;
   }
+  void AddRtpHeaderExtension(const cricket::RtpHeaderExtension& ext) {
+    webrtc::RtpExtension webrtc_extension;
+    webrtc_extension.uri = ext.uri;
+    webrtc_extension.id = ext.id;
+    rtp_header_extensions_.push_back(webrtc_extension);
+    rtp_header_extensions_set_ = true;
+  }
   void ClearRtpHeaderExtensions() {
     rtp_header_extensions_.clear();
     rtp_header_extensions_set_ = true;