Add net-log entries when HttpStream jobs are forced to wait, and when they're delayed and resumed.

net/http/http_stream_factory_impl_job.cc

Index: net/http/http_stream_factory_impl_job.cc
diff --git a/net/http/http_stream_factory_impl_job.cc b/net/http/http_stream_factory_impl_job.cc
index 38497c131c9a946155de2b81476950208ef2b0e2..3d16279955b3fe7a465e78d9e399cbdb3a7ee4ab 100644
--- a/net/http/http_stream_factory_impl_job.cc
+++ b/net/http/http_stream_factory_impl_job.cc
@@ -134,6 +134,15 @@ std::unique_ptr<base::Value> NetLogHttpStreamJobCallback(
   return std::move(dict);
 }
 
+// Returns parameters associated with the start of a HTTP stream job.
+std::unique_ptr<base::Value> NetLogHttpStreamJobWaitingCallback(

[eroman, 2017/02/14 21:18:36]

Have you considered using NetLog::BoolCallback() ? (can save writing some boiler
plate for simple cases like this).
(https://cs.chromium.org/chromium/src/net/log/net_log.h?q=net_log.h&dr=CSs&l=172)

[Ryan Hamilton, 2017/02/14 21:42:37]

Oh nice! I didn't know that existed. Thanks!

+    bool should_wait,
+    NetLogCaptureMode /* capture_mode */) {
+  std::unique_ptr<base::DictionaryValue> dict(new base::DictionaryValue());
+  dict->SetBoolean("should_wait", should_wait);
+  return std::move(dict);
+}
+
 // Returns parameters associated with the Proto (with NPN negotiation) of a HTTP
 // stream.
 std::unique_ptr<base::Value> NetLogHttpStreamProtoCallback(
@@ -809,13 +818,18 @@ bool HttpStreamFactoryImpl::Job::ShouldForceQuic() const {
 
 int HttpStreamFactoryImpl::Job::DoWait() {
   next_state_ = STATE_WAIT_COMPLETE;
-  if (delegate_->ShouldWait(this))
+  bool should_wait = delegate_->ShouldWait(this);
+  net_log_.BeginEvent(
+      NetLogEventType::HTTP_STREAM_JOB_WAITING,
+      base::Bind(&NetLogHttpStreamJobWaitingCallback, should_wait));
+  if (should_wait)
     return ERR_IO_PENDING;
 
   return OK;
 }
 
 int HttpStreamFactoryImpl::Job::DoWaitComplete(int result) {
+  net_log_.EndEvent(NetLogEventType::HTTP_STREAM_JOB_WAITING);
   DCHECK_EQ(OK, result);
   next_state_ = STATE_INIT_CONNECTION;
   return OK;