From 5bf9def61b916477898dd1d33f0f34b2c8df7056 Mon Sep 17 00:00:00 2001
From: hbos <hbos@webrtc.org>
Date: Mon, 20 Mar 2017 03:14:14 -0700
Subject: [PATCH] RTCStatsCollector: Remove closed channels from opened set.

This is a problem if a data channel is re-opened or a new data channel
occupies the same space in memory as a previously closed data channel.

Unittest updated to cover this (failed before fix, now passes).

BUG=webrtc:7181

Review-Url: https://codereview.webrtc.org/2746393003
Cr-Commit-Position: refs/heads/master@{#17304}
---
 webrtc/pc/rtcstatscollector.cc          |  5 ++--
 webrtc/pc/rtcstatscollector_unittest.cc | 33 +++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/webrtc/pc/rtcstatscollector.cc b/webrtc/pc/rtcstatscollector.cc
index 347bca53ea..d9da0729ed 100644
--- a/webrtc/pc/rtcstatscollector.cc
+++ b/webrtc/pc/rtcstatscollector.cc
@@ -1235,9 +1235,8 @@ void RTCStatsCollector::OnDataChannelClosed(DataChannel* channel) {
   RTC_DCHECK(signaling_thread_->IsCurrent());
   // Only channels that have been fully opened (and have increased the
   // |data_channels_opened_| counter) increase the closed counter.
-  if (internal_record_.opened_data_channels.find(
-          reinterpret_cast<uintptr_t>(channel)) !=
-      internal_record_.opened_data_channels.end()) {
+  if (internal_record_.opened_data_channels.erase(
+          reinterpret_cast<uintptr_t>(channel))) {
     ++internal_record_.data_channels_closed;
   }
 }
diff --git a/webrtc/pc/rtcstatscollector_unittest.cc b/webrtc/pc/rtcstatscollector_unittest.cc
index ea7b34a933..8fd00c6178 100644
--- a/webrtc/pc/rtcstatscollector_unittest.cc
+++ b/webrtc/pc/rtcstatscollector_unittest.cc
@@ -1463,6 +1463,39 @@ TEST_F(RTCStatsCollectorTest, CollectRTCPeerConnectionStats) {
               report->Get("RTCPeerConnection")->cast_to<
                   RTCPeerConnectionStats>());
   }
+
+  // Re-opening a data channel (or opening a new data channel that is re-using
+  // the same address in memory) should increase the opened count.
+  dummy_channel_b->SignalOpened(dummy_channel_b.get());
+
+  {
+    collector_->ClearCachedStatsReport();
+    rtc::scoped_refptr<const RTCStatsReport> report = GetStatsReport();
+    RTCPeerConnectionStats expected("RTCPeerConnection",
+                                    report->timestamp_us());
+    expected.data_channels_opened = 3;
+    expected.data_channels_closed = 1;
+    ASSERT_TRUE(report->Get("RTCPeerConnection"));
+    EXPECT_EQ(expected,
+              report->Get("RTCPeerConnection")->cast_to<
+                  RTCPeerConnectionStats>());
+  }
+
+  dummy_channel_a->SignalClosed(dummy_channel_a.get());
+  dummy_channel_b->SignalClosed(dummy_channel_b.get());
+
+  {
+    collector_->ClearCachedStatsReport();
+    rtc::scoped_refptr<const RTCStatsReport> report = GetStatsReport();
+    RTCPeerConnectionStats expected("RTCPeerConnection",
+                                    report->timestamp_us());
+    expected.data_channels_opened = 3;
+    expected.data_channels_closed = 3;
+    ASSERT_TRUE(report->Get("RTCPeerConnection"));
+    EXPECT_EQ(expected,
+              report->Get("RTCPeerConnection")->cast_to<
+                  RTCPeerConnectionStats>());
+  }
 }
 
 TEST_F(RTCStatsCollectorTest,