Fix issue of localDescription and remoteDescription getter.

public/platform/WebRTCSessionDescription.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 45 matching lines @@
 public:
     WebRTCSessionDescription() { }
     WebRTCSessionDescription(const WebRTCSessionDescription& other) { assign(other); }
     ~WebRTCSessionDescription() { reset(); }
 
     WebRTCSessionDescription& operator=(const WebRTCSessionDescription& other)
     {
         assign(other);
         return *this;
     }
+    bool operator==(const WebRTCSessionDescription& other)
+    {
+        return sdp() == other.sdp() && type() == other.type();
+    }
+    bool operator!=(const WebRTCSessionDescription& other)
+    {
+        return !(*this == other);
+    }
 
     BLINK_PLATFORM_EXPORT void assign(const WebRTCSessionDescription&);
 
     BLINK_PLATFORM_EXPORT void initialize(const WebString& type, const WebString& sdp);
     BLINK_PLATFORM_EXPORT void reset();
     bool isNull() const { return m_private.isNull(); }
 
     BLINK_PLATFORM_EXPORT WebString type() const;
     BLINK_PLATFORM_EXPORT void setType(const WebString&);
     BLINK_PLATFORM_EXPORT WebString sdp() const;
     BLINK_PLATFORM_EXPORT void setSDP(const WebString&);
 
 #if BLINK_IMPLEMENTATION
     WebRTCSessionDescription(WebString type, WebString sdp)
     {
         this->initialize(type, sdp);
     }
 #endif
 
 private:
     WebPrivatePtr<WebRTCSessionDescriptionPrivate> m_private;
 };
 
 } // namespace blink
 
 #endif // WebRTCSessionDescription_h