Bug 1706377 - Call VerifyTraffic for every network change event, r=necko-reviewers,valentin

For mozvpn, the data received in network change event is "up", not "changed", so we should call VerifyTraffic for every event for safe.
This patch also reduces http2.ping-timeout and http2.ping-threshold, since the original values are too long.

Differential Revision: https://phabricator.services.mozilla.com/D179681

modules/libpref/init/StaticPrefList.yaml

@@ -12398,12 +12398,12 @@
 
 - name: network.http.http2.ping-threshold
   type: RelaxedAtomicInt32
-  value: 58
+  value: 20
   mirror: always
 
 - name: network.http.http2.ping-timeout
   type: RelaxedAtomicInt32
-  value: 8
+  value: 5
   mirror: always
 
 - name: network.http.http2.send-buffer-size

netwerk/protocol/http/Http2Session.cpp

@@ -2145,6 +2145,9 @@ nsresult Http2Session::RecvPing(Http2Session* self) {
   if (self->mInputFrameFlags & kFlag_ACK) {
     // presumably a reply to our timeout ping.. don't reply to it
     self->mPingSentEpoch = 0;
+    // We need to reset mPreviousUsed. If we don't, the next time
+    // Http2Session::SendPing is called, it will have no effect.
+    self->mPreviousUsed = false;
   } else {
     // reply with a ack'd ping
     self->GeneratePing(true);
@@ -4328,6 +4331,7 @@ nsresult Http2Session::PushBack(const char* buf, uint32_t len) {
 
 void Http2Session::SendPing() {
   MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  LOG(("Http2Session::SendPing %p mPreviousUsed=%d", this, mPreviousUsed));
 
   if (mPreviousUsed) {
     // alredy in progress, get out

netwerk/protocol/http/nsHttpHandler.cpp

@@ -2141,18 +2141,15 @@ nsHttpHandler::Observe(nsISupports* subject, const char* topic,
       mAltSvcCache->ClearAltServiceMappings();
     }
   } else if (!strcmp(topic, NS_NETWORK_LINK_TOPIC)) {
-    nsAutoCString converted = NS_ConvertUTF16toUTF8(data);
-    if (!strcmp(converted.get(), NS_NETWORK_LINK_DATA_CHANGED)) {
-      if (mConnMgr) {
-        rv = mConnMgr->PruneDeadConnections();
-        if (NS_FAILED(rv)) {
-          LOG(("    PruneDeadConnections failed (%08x)\n",
-               static_cast<uint32_t>(rv)));
-        }
-        rv = mConnMgr->VerifyTraffic();
-        if (NS_FAILED(rv)) {
-          LOG(("    VerifyTraffic failed (%08x)\n", static_cast<uint32_t>(rv)));
-        }
+    if (mConnMgr) {
+      rv = mConnMgr->PruneDeadConnections();
+      if (NS_FAILED(rv)) {
+        LOG(("    PruneDeadConnections failed (%08x)\n",
+             static_cast<uint32_t>(rv)));
+      }
+      rv = mConnMgr->VerifyTraffic();
+      if (NS_FAILED(rv)) {
+        LOG(("    VerifyTraffic failed (%08x)\n", static_cast<uint32_t>(rv)));
       }
     }
   } else if (!strcmp(topic, "application-background")) {