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

ios/chrome/browser/ios_chrome_io_thread.h

Index: ios/chrome/browser/ios_chrome_io_thread.h
diff --git a/ios/chrome/browser/ios_chrome_io_thread.h b/ios/chrome/browser/ios_chrome_io_thread.h
index 17c7faaca101e43a65364aede385c73f03fc3ad0..34d4507ed1baf2f5b69bfd3310fcc93df5809a01 100644
--- a/ios/chrome/browser/ios_chrome_io_thread.h
+++ b/ios/chrome/browser/ios_chrome_io_thread.h
@@ -141,6 +141,8 @@ class IOSChromeIOThread : public web::WebThreadDelegate {
 
     Optional<bool> enable_npn;
 
+    Optional<bool> enable_priority_dependencies;
+
     Optional<bool> enable_quic;
     Optional<bool> enable_quic_for_proxies;
     Optional<bool> quic_always_require_handshake_confirmation;
@@ -252,6 +254,10 @@ class IOSChromeIOThread : public web::WebThreadDelegate {
 
   void ChangedToOnTheRecordOnIOThread();
 
+  // Configure whether we set HTTP/2 dependencies from the
+  // net::RequestPriority.
+  void ConfigurePriorityDependencies();
+
   // Configures QUIC options based on the QUIC field trial group.
   void ConfigureQuic();