Remove key exchange code from JingleSession.

remoting/protocol/content_description.h

Index: remoting/protocol/content_description.h
diff --git a/remoting/protocol/content_description.h b/remoting/protocol/content_description.h
index 678da314ca7eaeb081f6a2e117b2526c6528e275..b102480ce2ad993846cce91c29c1a32e53da1ce9 100644
--- a/remoting/protocol/content_description.h
+++ b/remoting/protocol/content_description.h
@@ -28,7 +28,6 @@ class ContentDescription : public cricket::ContentDescription {
  public:
   ContentDescription(const CandidateSessionConfig* config,
                      const std::string& auth_token,
-                     const std::string& master_key,
                      const std::string& certificate);
   virtual ~ContentDescription();
 
@@ -37,7 +36,6 @@ class ContentDescription : public cricket::ContentDescription {
   }
 
   const std::string& auth_token() const { return auth_token_; }
-  const std::string& master_key() const { return master_key_; }
   const std::string& certificate() const { return certificate_; }
 
   buzz::XmlElement* ToXml() const;
@@ -51,9 +49,6 @@ class ContentDescription : public cricket::ContentDescription {
   // context.
   std::string auth_token_;
 
-  // Master key used for the session encrypted with the hosts key.
-  std::string master_key_;
-
   std::string certificate_;
 };