[WS] Handle no handshake stream in PerformUpgrade().

The vast majority of recent crash reports point to line 190:
  CHECK(on_handshake_stream_created_has_been_called_);

Next branch cut is around the corner and this is still number one //net
crasher on M69.  https://crrev.com/c/940463 has been clearly identified
as the culprit.  Much pondering was still not enough to understand the
real underlying cause of this crash since the last branch point.  I
propose to be defensive in WebsocketStream.  While this is not the ideal
solution, I am not hopeful that we will find anything better any time
soon.  This approach allows the request to fail safely, while still
retaining the new WebSocket over HTTP/2 functionality.

Bug: 850183
Change-Id: I21a7c3919466c4339bebce41ee8ad1342fb9c179
Reviewed-on: https://chromium-review.googlesource.com/1140916
Commit-Queue: Bence Béky <bnc@chromium.org>
Reviewed-by: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576510}

net/websockets/websocket_stream.cc

@@ -120,7 +120,6 @@ class WebSocketStreamRequestImpl : public WebSocketStreamRequestAPI {
                                             kTrafficAnnotation)),
         connect_delegate_(std::move(connect_delegate)),
         handshake_stream_(nullptr),
-        on_handshake_stream_created_has_been_called_(false),
         perform_upgrade_has_been_called_(false),
         api_delegate_(std::move(api_delegate)) {
     create_helper->set_stream_request(this);
@@ -187,15 +186,20 @@ class WebSocketStreamRequestImpl : public WebSocketStreamRequestAPI {
   void PerformUpgrade() {
     DCHECK(timer_);
     CHECK(!perform_upgrade_has_been_called_);
-    CHECK(on_handshake_stream_created_has_been_called_);
     // TODO(bnc): Change to DCHECK after https://crbug.com/850183 is fixed.
-    CHECK(handshake_stream_);
     CHECK(connect_delegate_);
 
     perform_upgrade_has_been_called_ = true;
 
     timer_->Stop();
 
+    if (!handshake_stream_) {
+      // TODO(https://crbug.com/850183):
+      // Find out why this can happen and make it stop.
+      ReportFailureWithMessage("No handshake stream has been created.");
+      return;
+    }
+
     std::unique_ptr<URLRequest> url_request = std::move(url_request_);
     WebSocketHandshakeStreamBase* handshake_stream = handshake_stream_;
     handshake_stream_ = nullptr;
@@ -267,8 +271,6 @@ class WebSocketStreamRequestImpl : public WebSocketStreamRequestAPI {
     // TODO(bnc): Change to DCHECK after https://crbug.com/850183 is fixed.
     CHECK(handshake_stream);
 
-    on_handshake_stream_created_has_been_called_ = true;
-
     handshake_stream_ = handshake_stream;
   }
 
@@ -291,7 +293,6 @@ class WebSocketStreamRequestImpl : public WebSocketStreamRequestAPI {
   WebSocketHandshakeStreamBase* handshake_stream_;
 
   // TODO(bnc): Remove after https://crbug.com/850183 is fixed.
-  bool on_handshake_stream_created_has_been_called_;
   bool perform_upgrade_has_been_called_;
 
   // The failure message supplied by WebSocketBasicHandshakeStream, if any.