Replace the easy cases of VERIFY usage.

webrtc/pc/peerconnection.cc

Index: webrtc/pc/peerconnection.cc
diff --git a/webrtc/pc/peerconnection.cc b/webrtc/pc/peerconnection.cc
index cbd0d4b25a861b788e7f65d478ebf749ba90c1b6..1f84dbfd308ca20551ae02d6dc63894d17fc76c4 100644
--- a/webrtc/pc/peerconnection.cc
+++ b/webrtc/pc/peerconnection.cc
@@ -1014,10 +1014,7 @@ bool PeerConnection::GetStats(StatsObserver* observer,
                               StatsOutputLevel level) {
   TRACE_EVENT0("webrtc", "PeerConnection::GetStats");
   RTC_DCHECK(signaling_thread()->IsCurrent());
-  if (!VERIFY(observer != NULL)) {
-    LOG(LS_ERROR) << "GetStats - observer is NULL.";
-    return false;
-  }
+  RTC_DCHECK(observer != nullptr);

[kwiberg-webrtc, 2017/01/30 10:12:49]

RTC_DCHECK_NE? Or will that not compile?

(You could also check just "observer", with implicit pointer->bool conversion,
but I'll leave that style choice up to you.)

Are you sure these will never trigger? Otherwise we'll get crashes here that we
didn't get before.

[nisse-webrtc, 2017/01/30 10:58:41]

It fails to compile, with errors related to << and MakeCheckOpString.
I'll change to the more concise implicit bool conversion.
I'm not sure of anything... At least, there's nothing in the comments in
peerconnectioninterface.h to indicate that the observers are optional. Who
should I ask?

 
   stats_->UpdateStats(level);
   // The StatsCollector is used to tell if a track is valid because it may
@@ -1097,10 +1094,7 @@ PeerConnection::CreateDataChannel(
 void PeerConnection::CreateOffer(CreateSessionDescriptionObserver* observer,
                                  const MediaConstraintsInterface* constraints) {
   TRACE_EVENT0("webrtc", "PeerConnection::CreateOffer");
-  if (!VERIFY(observer != nullptr)) {
-    LOG(LS_ERROR) << "CreateOffer - observer is NULL.";
-    return;
-  }
+  RTC_DCHECK(observer != nullptr);
   RTCOfferAnswerOptions options;
 
   bool value;
@@ -1149,10 +1143,7 @@ void PeerConnection::CreateOffer(CreateSessionDescriptionObserver* observer,
 void PeerConnection::CreateOffer(CreateSessionDescriptionObserver* observer,
                                  const RTCOfferAnswerOptions& options) {
   TRACE_EVENT0("webrtc", "PeerConnection::CreateOffer");
-  if (!VERIFY(observer != nullptr)) {
-    LOG(LS_ERROR) << "CreateOffer - observer is NULL.";
-    return;
-  }
+  RTC_DCHECK(observer != nullptr);
 
   cricket::MediaSessionOptions session_options;
   if (!GetOptionsForOffer(options, &session_options)) {
@@ -1169,10 +1160,7 @@ void PeerConnection::CreateAnswer(
     CreateSessionDescriptionObserver* observer,
     const MediaConstraintsInterface* constraints) {
   TRACE_EVENT0("webrtc", "PeerConnection::CreateAnswer");
-  if (!VERIFY(observer != nullptr)) {
-    LOG(LS_ERROR) << "CreateAnswer - observer is NULL.";
-    return;
-  }
+  RTC_DCHECK(observer != nullptr);
 
   cricket::MediaSessionOptions session_options;
   if (!GetOptionsForAnswer(constraints, &session_options)) {
@@ -1188,10 +1176,7 @@ void PeerConnection::CreateAnswer(
 void PeerConnection::CreateAnswer(CreateSessionDescriptionObserver* observer,
                                   const RTCOfferAnswerOptions& options) {
   TRACE_EVENT0("webrtc", "PeerConnection::CreateAnswer");
-  if (!VERIFY(observer != nullptr)) {
-    LOG(LS_ERROR) << "CreateAnswer - observer is NULL.";
-    return;
-  }
+  RTC_DCHECK(observer != nullptr);
 
   cricket::MediaSessionOptions session_options;
   if (!GetOptionsForAnswer(options, &session_options)) {
@@ -1211,10 +1196,7 @@ void PeerConnection::SetLocalDescription(
   if (IsClosed()) {
     return;
   }
-  if (!VERIFY(observer != nullptr)) {
-    LOG(LS_ERROR) << "SetLocalDescription - observer is NULL.";
-    return;
-  }
+  RTC_DCHECK(observer != nullptr);
   if (!desc) {
     PostSetSessionDescriptionFailure(observer, "SessionDescription is NULL.");
     return;
@@ -1293,10 +1275,7 @@ void PeerConnection::SetRemoteDescription(
   if (IsClosed()) {
     return;
   }
-  if (!VERIFY(observer != nullptr)) {
-    LOG(LS_ERROR) << "SetRemoteDescription - observer is NULL.";
-    return;
-  }
+  RTC_DCHECK(observer != nullptr);
   if (!desc) {
     PostSetSessionDescriptionFailure(observer, "SessionDescription is NULL.");
     return;
@@ -2190,7 +2169,8 @@ void PeerConnection::UpdateLocalRtpDataChannels(
     // track label is the same as |streamid|.
     const std::string& channel_label = params.sync_label;
     auto data_channel_it = rtp_data_channels_.find(channel_label);
-    if (!VERIFY(data_channel_it != rtp_data_channels_.end())) {
+    if (data_channel_it == rtp_data_channels_.end()) {
+      LOG(LS_ERROR) << "channel label not found";
       continue;
     }
     // Set the SSRC the data channel should use for sending.