Make RTCStatsReport::ToString() return JSON-parseable string.

webrtc/pc/rtcstatscollector_unittest.cc

Index: webrtc/pc/rtcstatscollector_unittest.cc
diff --git a/webrtc/pc/rtcstatscollector_unittest.cc b/webrtc/pc/rtcstatscollector_unittest.cc
index 92024ad18dc8dd2505c6ec7fea37764742041009..8dc4a9702cdd0fd686fdbae5f237c3f351675985 100644
--- a/webrtc/pc/rtcstatscollector_unittest.cc
+++ b/webrtc/pc/rtcstatscollector_unittest.cc
@@ -54,51 +54,51 @@ namespace webrtc {
 
 // These are used by gtest code, such as if |EXPECT_EQ| fails.
 void PrintTo(const RTCCertificateStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCCodecStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCDataChannelStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCIceCandidatePairStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCLocalIceCandidateStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCRemoteIceCandidateStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCPeerConnectionStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCMediaStreamStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCMediaStreamTrackStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCInboundRTPStreamStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCOutboundRTPStreamStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 void PrintTo(const RTCTransportStats& stats, ::std::ostream* os) {
-  *os << stats.ToString();
+  *os << stats.ToJson();
 }
 
 namespace {