Backed out changeset 91f2821b4bfa (bug 1563313) for xpcshell failures CLOSED TREE

modules/libpref/init/StaticPrefList.h

@@ -6989,6 +6989,13 @@ VARCACHE_PREF(
   RelaxedAtomicBool, false
 )
 
+VARCACHE_PREF(
+  Live,
+  "network.delay.tracking.load",
+  network_delay_tracking_load,
+  uint32_t, 0
+)
+
 // Max time to shutdown the resolver threads
 VARCACHE_PREF(
   Live,

netwerk/protocol/http/nsHttpChannel.cpp

@@ -6495,6 +6495,8 @@ nsHttpChannel::AsyncOpen(nsIStreamListener* aListener) {
 
 nsresult nsHttpChannel::AsyncOpenFinal(TimeStamp aTimeStamp) {
   // Added due to PauseTask/DelayHttpChannel
+  nsresult rv;
+
   if (mLoadGroup) mLoadGroup->AddRequest(this, nullptr);
 
   // record asyncopen time unconditionally and clear it if we
@@ -6509,39 +6511,6 @@ nsresult nsHttpChannel::AsyncOpenFinal(TimeStamp aTimeStamp) {
   // just once and early, AsyncOpen is the best place.
   mCustomAuthHeader = mRequestHead.HasHeader(nsHttp::Authorization);
 
-  if (!NS_ShouldClassifyChannel(this)) {
-    return MaybeResolveProxyAndBeginConnect();
-  }
-
-  // We are about to do an async lookup to check if the URI is a tracker. If
-  // yes, this channel will be canceled by channel classifier.  Chances are the
-  // lookup is not needed so CheckIsTrackerWithLocalTable() will return an
-  // error and then we can MaybeResolveProxyAndBeginConnect() right away.
-  RefPtr<nsHttpChannel> self = this;
-  bool willCallback = NS_SUCCEEDED(
-      AsyncUrlChannelClassifier::CheckChannel(this, [self]() -> void {
-        nsresult rv = self->MaybeResolveProxyAndBeginConnect();
-        if (NS_FAILED(rv)) {
-          // Since this error is thrown asynchronously so that the caller
-          // of BeginConnect() will not do clean up for us. We have to do
-          // it on our own.
-          self->CloseCacheEntry(false);
-          Unused << self->AsyncAbort(rv);
-        }
-      }));
-
-  if (!willCallback) {
-    // We can do MaybeResolveProxyAndBeginConnect immediately if
-    // CheckIsTrackerWithLocalTable is failed. Note that we don't need to
-    // handle the failure because BeginConnect() will return synchronously and
-    // the caller will be responsible for handling it.
-    return MaybeResolveProxyAndBeginConnect();
-  }
-
-  return NS_OK;
-}
-
-nsresult nsHttpChannel::MaybeResolveProxyAndBeginConnect() {
   // The common case for HTTP channels is to begin proxy resolution and return
   // at this point. The only time we know mProxyInfo already is if we're
   // proxying a non-http protocol like ftp. We don't need to discover proxy
@@ -6552,7 +6521,7 @@ nsresult nsHttpChannel::MaybeResolveProxyAndBeginConnect() {
     return NS_OK;
   }
 
-  nsresult rv = BeginConnect();
+  rv = BeginConnect();
   if (NS_FAILED(rv)) {
     CloseCacheEntry(false);
     Unused << AsyncAbort(rv);
@@ -6770,30 +6739,57 @@ nsresult nsHttpChannel::BeginConnect() {
     return mStatus;
   }
 
-  if (mChannelClassifierCancellationPending) {
-    LOG(
-        ("Waiting for safe-browsing protection cancellation in BeginConnect "
-         "[this=%p]\n",
-         this));
-    return NS_OK;
+  if (!NS_ShouldClassifyChannel(this)) {
+    MaybeStartDNSPrefetch();
+    return ContinueBeginConnectWithResult();
   }
 
-  ReEvaluateReferrerAfterTrackingStatusIsKnown();
+  // We are about to do an async lookup to check if the URI is a
+  // tracker. If yes, this channel will be canceled by channel classifier.
+  // Chances are the lookup is not needed so CheckIsTrackerWithLocalTable()
+  // will return an error and then we can BeginConnectActual() right away.
+  RefPtr<nsHttpChannel> self = this;
+  bool willCallback = NS_SUCCEEDED(
+      AsyncUrlChannelClassifier::CheckChannel(this, [self]() -> void {
+        auto nextFunc = [self]() -> void {
+          nsresult rv = self->BeginConnectActual();
+          if (NS_FAILED(rv)) {
+            // Since this error is thrown asynchronously so that the caller
+            // of BeginConnect() will not do clean up for us. We have to do
+            // it on our own.
+            self->CloseCacheEntry(false);
+            Unused << self->AsyncAbort(rv);
+          }
+        };
 
-  MaybeStartDNSPrefetch();
+        uint32_t delayMillisec = StaticPrefs::network_delay_tracking_load();
+        if (self->IsThirdPartyTrackingResource() && delayMillisec) {
+          nsCOMPtr<nsIRunnable> runnable = NS_NewRunnableFunction(
+              "nsHttpChannel::BeginConnect-delayed", nextFunc);
+          nsresult rv = NS_DelayedDispatchToCurrentThread(runnable.forget(),
+                                                          delayMillisec);
+          if (NS_SUCCEEDED(rv)) {
+            LOG(
+                ("nsHttpChannel::BeginConnect delaying 3rd-party tracking "
+                 "resource for %u ms [this=%p]",
+                 delayMillisec, self.get()));
+            return;
+          }
+          LOG(("nsHttpChannel::BeginConnect unable to delay loading. [this=%p]",
+               self.get()));
+        }
 
-  rv = ContinueBeginConnectWithResult();
-  if (NS_FAILED(rv)) {
-    return rv;
+        nextFunc();
+      }));
+
+  if (!willCallback) {
+    // We can do BeginConnectActual immediately if CheckIsTrackerWithLocalTable
+    // is failed. Note that we don't need to handle the failure because
+    // BeginConnect() will return synchronously and the caller will be
+    // responsible for handling it.
+    return BeginConnectActual();
   }
 
-  // Start nsChannelClassifier to catch phishing and malware URIs.
-  RefPtr<nsChannelClassifier> channelClassifier =
-      GetOrCreateChannelClassifier();
-  LOG(("nsHttpChannel::Starting nsChannelClassifier %p [this=%p]",
-       channelClassifier.get(), this));
-  channelClassifier->Start();
-
   return NS_OK;
 }
 
@@ -6823,6 +6819,40 @@ void nsHttpChannel::MaybeStartDNSPrefetch() {
   }
 }
 
+nsresult nsHttpChannel::BeginConnectActual() {
+  if (mCanceled) {
+    return mStatus;
+  }
+
+  AUTO_PROFILER_LABEL("nsHttpChannel::BeginConnectActual", NETWORK);
+
+  if (mChannelClassifierCancellationPending) {
+    LOG(
+        ("Waiting for safe-browsing protection cancellation in "
+         "BeginConnectActual [this=%p]\n",
+         this));
+    return NS_OK;
+  }
+
+  ReEvaluateReferrerAfterTrackingStatusIsKnown();
+
+  MaybeStartDNSPrefetch();
+
+  nsresult rv = ContinueBeginConnectWithResult();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // Start nsChannelClassifier to catch phishing and malware URIs.
+  RefPtr<nsChannelClassifier> channelClassifier =
+      GetOrCreateChannelClassifier();
+  LOG(("nsHttpChannel::Starting nsChannelClassifier %p [this=%p]",
+       channelClassifier.get(), this));
+  channelClassifier->Start();
+
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsHttpChannel::GetEncodedBodySize(uint64_t* aEncodedBodySize) {
   if (mCacheEntry && !mCacheEntryIsWriteOnly) {

netwerk/protocol/http/nsHttpChannel.h

@@ -316,13 +316,13 @@ class nsHttpChannel final : public HttpBaseChannel,
 
   // Connections will only be established in this function.
   // (including DNS prefetch and speculative connection.)
-  nsresult MaybeResolveProxyAndBeginConnect();
+  nsresult BeginConnectActual();
   void MaybeStartDNSPrefetch();
 
-  // We might synchronously or asynchronously call BeginConnect,
+  // We might synchronously or asynchronously call BeginConnectActual,
   // which includes DNS prefetch and speculative connection, according to
   // whether an async tracker lookup is required. If the tracker lookup
-  // is required, this funciton will just return NS_OK and BeginConnect()
+  // is required, this funciton will just return NS_OK and BeginConnectActual()
   // will be called when callback. See Bug 1325054 for more information.
   nsresult BeginConnect();
   MOZ_MUST_USE nsresult ContinueBeginConnectWithResult();
@@ -587,7 +587,7 @@ class nsHttpChannel final : public HttpBaseChannel,
   // nsChannelClassifier checks this channel's URI against
   // the URI classifier service.
   // nsChannelClassifier will be invoked twice in InitLocalBlockList() and
-  // BeginConnect(), so save the nsChannelClassifier here to keep the
+  // BeginConnectActual(), so save the nsChannelClassifier here to keep the
   // state of whether tracking protection is enabled or not.
   RefPtr<nsChannelClassifier> mChannelClassifier;