Fix bug in net::RequestPriority -> HTTP/2 dependency conversion.

ios/chrome/browser/ios_chrome_io_thread.mm

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ios/chrome/browser/ios_chrome_io_thread.h"
 
 #include <stddef.h>
 
 #include <utility>
 #include <vector>
@@ skipping 119 matching lines @@
 // Field trial for network quality estimator. Seeds RTT and downstream
 // throughput observations with values that correspond to the connection type
 // determined by the operating system.
 const char kNetworkQualityEstimatorFieldTrialName[] = "NetworkQualityEstimator";
 
 // Field trial for NPN.
 const char kNpnTrialName[] = "NPN";
 const char kNpnTrialEnabledGroupNamePrefix[] = "Enable";
 const char kNpnTrialDisabledGroupNamePrefix[] = "Disable";
 
+// Field trial for priority dependencies.
+const char kSpdyDependenciesFieldTrial[] = "SpdyEnableDependencies";
+const char kSpdyDependenciesFieldTrialEnable[] = "Enable";
+const char kSpdyDepencenciesFieldTrialDisable[] = "Disable";
+
 // Used for the "system" URLRequestContext.
 class SystemURLRequestContext : public net::URLRequestContext {
  public:
   SystemURLRequestContext() {
 #if defined(USE_NSS_VERIFIER)
     net::SetURLRequestContextForNSSHttpIO(this);
 #endif
   }
 
  private:
@@ skipping 298 matching lines @@
     globals_->testing_fixed_http_port =
         GetSwitchValueAsInt(command_line, switches::kIOSTestingFixedHttpPort);
   }
   if (command_line.HasSwitch(switches::kIOSTestingFixedHttpsPort)) {
     globals_->testing_fixed_https_port =
         GetSwitchValueAsInt(command_line, switches::kIOSTestingFixedHttpsPort);
   }
   ConfigureAltSvcGlobals(
       base::FieldTrialList::FindFullName(kAltSvcFieldTrialName), globals_);
   ConfigureQuic();
+  ConfigurePriorityDependencies();
   InitializeNetworkOptions();
 
   const version_info::Channel channel = ::GetChannel();
   if (channel == version_info::Channel::UNKNOWN ||
       channel == version_info::Channel::CANARY ||
       channel == version_info::Channel::DEV) {
     globals_->url_request_backoff_manager.reset(
         new net::URLRequestBackoffManager());
   }
 
@@ skipping 172 matching lines @@
 
   globals.enable_spdy31.CopyToIfSet(&params->enable_spdy31);
   globals.enable_http2.CopyToIfSet(&params->enable_http2);
   globals.parse_alternative_services.CopyToIfSet(
       &params->parse_alternative_services);
   globals.enable_alternative_service_with_different_host.CopyToIfSet(
       &params->enable_alternative_service_with_different_host);
 
   globals.enable_npn.CopyToIfSet(&params->enable_npn);
 
+  globals.enable_priority_dependencies.CopyToIfSet(
+      &params->enable_priority_dependencies);
+
   globals.enable_quic.CopyToIfSet(&params->enable_quic);
   globals.enable_quic_for_proxies.CopyToIfSet(&params->enable_quic_for_proxies);
   globals.quic_always_require_handshake_confirmation.CopyToIfSet(
       &params->quic_always_require_handshake_confirmation);
   globals.quic_disable_connection_pooling.CopyToIfSet(
       &params->quic_disable_connection_pooling);
   globals.quic_load_server_info_timeout_srtt_multiplier.CopyToIfSet(
       &params->quic_load_server_info_timeout_srtt_multiplier);
   globals.quic_enable_connection_racing.CopyToIfSet(
       &params->quic_enable_connection_racing);
@@ skipping 60 matching lines @@
   DCHECK(system_proxy_config_service_.get());
 
   globals_->system_proxy_service = ios::ProxyServiceFactory::CreateProxyService(
       net_log_, nullptr, globals_->system_network_delegate.get(),
       std::move(system_proxy_config_service_), true /* quick_check_enabled */);
 
   globals_->system_request_context.reset(
       ConstructSystemRequestContext(globals_, net_log_));
 }
 
+void IOSChromeIOThread::ConfigurePriorityDependencies() {
+  std::string group =
+      base::FieldTrialList::FindFullName(kSpdyDependenciesFieldTrial);
+  if (group == kSpdyDependenciesFieldTrialEnable) {
+    globals_->enable_priority_dependencies.set(true);
+  } else if (group == kSpdyDepencenciesFieldTrialDisable) {
+    globals_->enable_priority_dependencies.set(false);
+  }
+}
+
 void IOSChromeIOThread::ConfigureQuic() {
   // Always fetch the field trial group to ensure it is reported correctly.
   // The command line flags will be associated with a group that is reported
   // so long as trial is actually queried.
   std::string group = base::FieldTrialList::FindFullName(kQuicFieldTrialName);
   VariationParameters params;
   if (!variations::GetVariationParams(kQuicFieldTrialName, &params)) {
     params.clear();
   }
 
@@ skipping 284 matching lines @@
 
   globals->system_http_network_session.reset(
       new net::HttpNetworkSession(system_params));
   globals->system_http_transaction_factory.reset(
       new net::HttpNetworkLayer(globals->system_http_network_session.get()));
   context->set_http_transaction_factory(
       globals->system_http_transaction_factory.get());
 
   return context;
 }