Split QUICHE build rules into their own file and build target

This moves nearly all net/third_party/quiche source files into
//net/third_party/quiche/BUILD.gn, so that they can be given visibility for
absl later.

Change-Id: Ifa2902002f5f7a2b1b5005f6c3f337439af69ce3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2020686Reviewed-by: Ryan Hamilton <rch@chromium.org>
Reviewed-by: Bence Béky <bnc@chromium.org>
Commit-Queue: Victor Vasiliev <vasilvv@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735250}

net/third_party/quiche/README.chromium

+Name: QUICHE
+URL: https://quiche.googlesource.com/quiche
+Version: git
+License: BSD
+License File: src/LICENSE
+Security Critical: yes
+
+Description:
+This is QUICHE, Google's implementation of QUIC, HTTP/2 and SPDY protocols.

third_party/quic_trace/BUILD.gn

@@ -4,12 +4,8 @@ import("//third_party/protobuf/proto_library.gni")
 # use the lite runtime.
 action("quic_trace_proto_lite_runtime") {
   script = "append_lite_runtime.py"
-  inputs = [
-    "src/lib/quic_trace.proto",
-  ]
-  outputs = [
-    "$target_gen_dir/quic_trace.proto",
-  ]
+  inputs = [ "src/lib/quic_trace.proto" ]
+  outputs = [ "$target_gen_dir/quic_trace.proto" ]
   args =
       rebase_path(inputs, root_build_dir) + rebase_path(outputs, root_build_dir)
 }
@@ -18,11 +14,12 @@ proto_library("quic_trace_proto") {
   # QUIC trace is only used in unit tests and stand-alone command line tools.
   # It is not linked into the network stack itself due to the Cronet binary
   # size concerns.
-  visibility = [ "//net:quic_test_tools" ]
-
-  sources = [
-    "$target_gen_dir/quic_trace.proto",
+  visibility = [
+    "//net:quic_test_tools",
+    "//net/third_party/quiche:quic_test_tools_core",
   ]
+
+  sources = [ "$target_gen_dir/quic_trace.proto" ]
   proto_deps = [ ":quic_trace_proto_lite_runtime" ]
   component_build_force_source_set = true
   testonly = true