Revert of RTCOutboundRTPStreamStats added.

webrtc/api/stats/rtcstatsreport.h

Index: webrtc/api/stats/rtcstatsreport.h
diff --git a/webrtc/api/stats/rtcstatsreport.h b/webrtc/api/stats/rtcstatsreport.h
index 34f0d545ffce97e88a41006e2280796569af3a73..beb865035394f65b4a28bee9d26a7f2c8aa6bb96 100644
--- a/webrtc/api/stats/rtcstatsreport.h
+++ b/webrtc/api/stats/rtcstatsreport.h
@@ -36,7 +36,6 @@
     ConstIterator& operator++();
     ConstIterator& operator++(int);
     const RTCStats& operator*() const;
-    const RTCStats* operator->() const;
     bool operator==(const ConstIterator& other) const;
     bool operator!=(const ConstIterator& other) const;
 
@@ -50,12 +49,11 @@
     StatsMap::const_iterator it_;
   };
 
-  static rtc::scoped_refptr<RTCStatsReport> Create(uint64_t timestamp_us);
+  static rtc::scoped_refptr<RTCStatsReport> Create();
 
-  explicit RTCStatsReport(uint64_t timestamp_us);
+  RTCStatsReport();
   RTCStatsReport(const RTCStatsReport& other) = delete;
 
-  uint64_t timestamp_us() const { return timestamp_us_; }
   bool AddStats(std::unique_ptr<const RTCStats> stats);
   const RTCStats* Get(const std::string& id) const;
   size_t size() const { return stats_.size(); }
@@ -79,16 +77,11 @@
     return stats_of_type;
   }
 
-  // Creates a human readable string representation of the report, listing all
-  // of its stats objects.
-  std::string ToString() const;
-
   friend class rtc::RefCountedObject<RTCStatsReport>;
 
  private:
   ~RTCStatsReport() override;
 
-  uint64_t timestamp_us_;
   StatsMap stats_;
 };