add customized printing setting for headless

headless/BUILD.gn

 # 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.
 
 import("//build/config/chrome_build.gni")
 import("//headless/headless.gni")
 import("//build/util/process_version.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//printing/features/features.gni")
 import("//testing/test.gni")
@@ skipping 11 matching lines @@
 group("headless") {
   deps = [
     "//headless:headless_lib",
   ]
 }
 
 repack("pak") {
   sources = [
     "$root_gen_dir/blink/public/resources/blink_image_resources_100_percent.pak",
     "$root_gen_dir/blink/public/resources/blink_resources.pak",
+    "$root_gen_dir/components/components_resources.pak",
     "$root_gen_dir/components/strings/components_strings_en-US.pak",
     "$root_gen_dir/content/app/resources/content_resources_100_percent.pak",
     "$root_gen_dir/content/app/strings/content_strings_en-US.pak",
     "$root_gen_dir/content/browser/devtools/devtools_resources.pak",
     "$root_gen_dir/content/browser/tracing/tracing_resources.pak",
     "$root_gen_dir/content/content_resources.pak",
     "$root_gen_dir/headless/headless_lib_resources.pak",
     "$root_gen_dir/net/net_resources.pak",
     "$root_gen_dir/ui/resources/ui_resources_100_percent.pak",
     "$root_gen_dir/ui/resources/webui_resources.pak",
     "$root_gen_dir/ui/strings/app_locale_settings_en-US.pak",
     "$root_gen_dir/ui/strings/ui_strings_en-US.pak",
   ]
 
   if (is_chrome_branded) {
     sources += [ "${root_gen_dir}/components/strings/components_google_chrome_strings_en-US.pak" ]
   } else {
     sources += [ "${root_gen_dir}/components/strings/components_chromium_strings_en-US.pak" ]
   }
 
   deps = [
     ":resources",
+    "//components/resources:components_resources",
     "//components/strings",
     "//content:resources",
     "//content/app/resources",
     "//content/app/strings",
     "//content/browser/devtools:resources",
     "//content/browser/tracing:resources",
     "//net:net_resources",
     "//third_party/WebKit/public:image_resources",
     "//third_party/WebKit/public:resources",
     "//ui/resources",
@@ skipping 245 matching lines @@
       "lib/renderer/headless_print_web_view_helper_delegate.cc",
       "lib/renderer/headless_print_web_view_helper_delegate.h",
     ]
   }
 
   public_deps = [
     "//base",
     "//net",
   ]
 
+  if (enable_basic_printing) {
+    public_deps += [ "//skia" ]

[Sami, 2017/05/05 16:54:12]

This is probably fine if it's needed to fix a build error, but I'll just note
that embedders of headless shouldn't depend on skia to avoid build breaks due to
API churn.

[Wei Li, 2017/05/05 17:18:28]

drive-by: Should this be a deps instead? I don't see why headless lib needs to
expose skia?
btw, is it better to merge sections at line307, this one and line352 all
together?

[Lei Zhang, 2017/05/05 21:39:28]

It's not a deps entry because it is no the headless_lib target that needs it.
It's any dependents that #includes headless/lib/browser/headless_print_manager.h
that has problems.

As an example, components/constrained_window does the same thing, even though
the directory does not have a single skia #include.

[blundell, 2017/05/09 15:34:04]

I've been following this discussion, and I still don't really understand it. If
the target doesn't need to directly depend on or expose //skia, then it also
shouldn't need to have //skia as a public dependency. If the issue is that this
target is exposing its dependents to some intermediate target that then exposes
//skia, I believe that the following structure should have the same effect and
is cleaner from an encapsulation POV:
- the intermediate target lists //skia as a public dep
- this target lists the intermediate target as a public dep

Am I missing something here?

[jzfeng, 2017/05/10 06:55:09]

headless_lib need to expose //skia to make the target depend on it to build.
Among the current deps of headless_lib, several expose //skia. They are:
content/public/app:both
content/public/browser
content/public/child:child
content/public/common
ui/base
ui/display
ui/events/devices
So it wouldn't make much sense to expose one of them from headless_lib.

+  }
+
   deps = [
     ":gen_devtools_client_api",
     ":tab_socket",
     ":version_header",
     "//components/crash/content/browser",
     "//components/security_state/content",
     "//components/security_state/core",
     "//content/public/app:both",
     "//content/public/browser",
     "//content/public/child:child",
@@ skipping 52 matching lines @@
   sources = [
     "public/domains/types_unittest.cc",
     "public/util/deterministic_dispatcher_test.cc",
     "public/util/error_reporter_unittest.cc",
     "public/util/expedited_dispatcher_test.cc",
     "public/util/generic_url_request_job_test.cc",
     "public/util/testing/fake_managed_dispatch_url_request_job.cc",
     "public/util/testing/fake_managed_dispatch_url_request_job.h",
   ]
 
+  if (enable_basic_printing) {
+    sources += [ "lib/browser/headless_printing_unittest.cc" ]
+  }
+
   deps = [
     ":headless_lib",
     "//base/test:run_all_unittests",
     "//base/test:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }
 
 mojom("embedder_mojo_for_testing") {
@@ skipping 82 matching lines @@
 
   deps = [
     ":embedder_mojo_for_testing",
     ":headless_browser_tests_pak",
     "//base",
     "//content/test:test_support",
     "//headless:headless_lib",
     "//testing/gmock",
     "//testing/gtest",
   ]
+
+  if (enable_basic_printing) {
+    deps += [ "//pdf" ]
+  }
 }
 
 static_library("headless_shell_lib") {
   sources = [
     "app/headless_shell.cc",
     "app/headless_shell.h",
     "app/headless_shell_switches.cc",
     "app/headless_shell_switches.h",
     "app/shell_navigation_request.cc",
     "app/shell_navigation_request.h",
@@ skipping 38 matching lines @@
 
 executable("headless_example") {
   sources = [
     "app/headless_example.cc",
   ]
 
   deps = [
     "//headless:headless_shell_lib",
   ]
 }