[Bindings] Make maplike<> and setlike<> imply a readonly size attribute.

content/renderer/media/webrtc/rtc_stats.h

 // Copyright (c) 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_MEDIA_WEBRTC_RTC_STATS_H_
 #define CONTENT_RENDERER_MEDIA_WEBRTC_RTC_STATS_H_
 
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebRTCStats.h"
 #include "third_party/webrtc/api/stats/rtcstats.h"
 #include "third_party/webrtc/api/stats/rtcstatsreport.h"
 
 namespace content {
 
 class CONTENT_EXPORT RTCStatsReport : public blink::WebRTCStatsReport {
  public:
   RTCStatsReport(
       const scoped_refptr<const webrtc::RTCStatsReport>& stats_report);
   ~RTCStatsReport() override;
   std::unique_ptr<blink::WebRTCStatsReport> CopyHandle() const override;
 
   std::unique_ptr<blink::WebRTCStats> GetStats(
       blink::WebString id) const override;
   std::unique_ptr<blink::WebRTCStats> Next() override;
+  size_t Size() const override;
 
  private:
   const scoped_refptr<const webrtc::RTCStatsReport> stats_report_;
   webrtc::RTCStatsReport::ConstIterator it_;
   const webrtc::RTCStatsReport::ConstIterator end_;
 };
 
 class CONTENT_EXPORT RTCStats : public blink::WebRTCStats {
  public:
   RTCStats(const scoped_refptr<const webrtc::RTCStatsReport>& stats_owner,
@@ skipping 46 matching lines @@
   const scoped_refptr<const webrtc::RTCStatsReport> stats_owner_;
   // Pointer to member of a stats object that is owned by |stats_owner_|.
   const webrtc::RTCStatsMemberInterface* const member_;
 };
 
 CONTENT_EXPORT void WhitelistStatsForTesting(const char* type);
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_WEBRTC_RTC_STATS_H_