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

content/renderer/media/webrtc/rtc_stats.cc

 // 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.
 
 #include "content/renderer/media/webrtc/rtc_stats.h"
 
 #include <set>
 #include <string>
 
 #include "base/logging.h"
@@ skipping 77 matching lines @@
     const webrtc::RTCStats& next = *it_;
     ++it_;
     if (IsWhitelistedStats(next)) {
       return std::unique_ptr<blink::WebRTCStats>(
           new RTCStats(stats_report_, &next));
     }
   }
   return std::unique_ptr<blink::WebRTCStats>();
 }
 
+size_t RTCStatsReport::Size() const {
+  return stats_report_->size();
+}
+
 RTCStats::RTCStats(
     const scoped_refptr<const webrtc::RTCStatsReport>& stats_owner,
     const webrtc::RTCStats* stats)
     : stats_owner_(stats_owner),
       stats_(stats),
       stats_members_(stats->Members()) {
   DCHECK(stats_owner_);
   DCHECK(stats_);
   DCHECK(stats_owner_->Get(stats_->id()));
 }
@@ skipping 166 matching lines @@
   for (size_t i = 0; i < sequence.size(); ++i)
     web_sequence[i] = blink::WebString::FromUTF8(sequence[i]);
   return web_sequence;
 }
 
 void WhitelistStatsForTesting(const char* type) {
   GetStatsWhitelist()->WhitelistStatsForTesting(type);
 }
 
 }  // namespace content