Rename SignedExchangeHeaderParser to SignedExchangeSignatureHeaderField

See the below doc for the overall picture:
https://docs.google.com/document/d/1A458poqQsW8fD-Zur601-eokpxPA6zkUzTiquo2eI9E/edit

Bug: 847315
Change-Id: I36858f1cf273504e003c191d391fc8d9dce58f8f
Reviewed-on: https://chromium-review.googlesource.com/1075839
Reviewed-by: Kunihiko Sakamoto <[email protected]>
Reviewed-by: Kinuko Yasuda <[email protected]>
Reviewed-by: Tsuyoshi Horo <[email protected]>
Commit-Queue: Kouhei Ueno <[email protected]>
Cr-Commit-Position: refs/heads/master@{#562343}
diff --git a/content/browser/BUILD.gn b/content/browser/BUILD.gn
index 7871d38..9b4ee7d9 100644
--- a/content/browser/BUILD.gn
+++ b/content/browser/BUILD.gn
@@ -1728,8 +1728,8 @@
     "web_package/signed_exchange_handler.h",
     "web_package/signed_exchange_header.cc",
     "web_package/signed_exchange_header.h",
-    "web_package/signed_exchange_header_parser.cc",
-    "web_package/signed_exchange_header_parser.h",
+    "web_package/signed_exchange_signature_header_field.cc",
+    "web_package/signed_exchange_signature_header_field.h",
     "web_package/signed_exchange_signature_verifier.cc",
     "web_package/signed_exchange_signature_verifier.h",
     "web_package/signed_exchange_url_loader_factory_for_non_network_service.cc",