GN rules: add libraries_specification_uri argument to the  compile_platform template.

Change-Id: I58ac93cdd99a86009bd3ab3c7b37157104ae8aa4
Reviewed-on: https://dart-review.googlesource.com/60145
Commit-Queue: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Zach Anderson <zra@google.com>
diff --git a/runtime/vm/BUILD.gn b/runtime/vm/BUILD.gn
index 037d5b5..a3f1640 100644
--- a/runtime/vm/BUILD.gn
+++ b/runtime/vm/BUILD.gn
@@ -302,28 +302,20 @@
 }
 
 compile_platform("vm_legacy_platform") {
-  sources = [
-    "../../sdk/lib/libraries.json",
-  ]
+  libraries_specification_uri = "../../sdk/lib/libraries.json"
 
   outputs = [
     "$root_out_dir/vm_platform.dill",
     "$root_out_dir/vm_outline.dill",
   ]
 
-  inputs = [
-    "../../sdk/lib/libraries.yaml",
-  ]
-
   args = [ "dart:core" ]
 }
 
 compile_platform("vm_platform") {
   add_implicit_vm_platform_dependency = false
 
-  sources = [
-    "../../sdk/lib/libraries.json",
-  ]
+  libraries_specification_uri = "../../sdk/lib/libraries.json"
 
   outputs = [
     "$root_out_dir/vm_platform_strong.dill",
diff --git a/utils/compile_platform.gni b/utils/compile_platform.gni
index 4601662..9c157b7 100644
--- a/utils/compile_platform.gni
+++ b/utils/compile_platform.gni
@@ -14,7 +14,8 @@
 _dart_root = get_path_info("..", "abspath")
 
 template("compile_platform") {
-  assert(defined(invoker.sources), "Need 'sources' in $target_name")
+  assert(defined(invoker.libraries_specification_uri),
+      "Need 'libraries_specification_uri' in $target_name")
   assert(defined(invoker.outputs), "Need 'outputs' in $target_name")
   assert(defined(invoker.args), "Need 'args' in $target_name")
   if (defined(invoker.single_root_scheme)) {
@@ -43,16 +44,6 @@
   action(target_name) {
     script = "$_dart_root/tools/compile_platform.py"
 
-    # Note: invoker.sources contains a library-specification URI. It's not
-    # listed as a source of the action because it may be written using a custom
-    # URI when this template is invoked with a single_root_scheme.
-    #
-    # The compile_platform script, however, generates a deps file which includes
-    # the corresponding library-specification file URI, so we rely on that to
-    # track the required dependencies.
-    # TODO(sigmund): replace "sources" with a "library_specification_uri"
-    # argument to make this clearer.
-
     outputs = invoker.outputs
 
     inputs = []
@@ -97,9 +88,9 @@
       args += ["--single-root-base=" + invoker.single_root_base]
     }
     if (defined(invoker.single_root_scheme)) {
-      args += invoker.sources
+      args += [invoker.libraries_specification_uri]
     } else {
-      args += rebase_path(invoker.sources, root_build_dir)
+      args += [rebase_path(invoker.libraries_specification_uri, root_build_dir)]
     }
     args += rebase_path(outputs, root_build_dir)
   }
diff --git a/utils/compiler/BUILD.gn b/utils/compiler/BUILD.gn
index 428a2e0..c94d732 100644
--- a/utils/compiler/BUILD.gn
+++ b/utils/compiler/BUILD.gn
@@ -78,9 +78,7 @@
 compile_platform("compile_dart2js_platform") {
   single_root_scheme = "org-dartlang-sdk"
   single_root_base = "../../"
-  sources = [
-    "org-dartlang-sdk:///sdk/lib/libraries.json",
-  ]
+  libraries_specification_uri = "org-dartlang-sdk:///sdk/lib/libraries.json"
 
   outputs = [
     "$root_out_dir/dart2js_platform.dill",
@@ -96,9 +94,7 @@
 compile_platform("compile_dart2js_platform_strong") {
   single_root_scheme = "org-dartlang-sdk"
   single_root_base = "../../"
-  sources = [
-    "org-dartlang-sdk:///sdk/lib/libraries.json",
-  ]
+  libraries_specification_uri = "org-dartlang-sdk:///sdk/lib/libraries.json"
 
   outputs = [
     "$root_out_dir/dart2js_platform_strong.dill",
@@ -115,9 +111,7 @@
 compile_platform("compile_dart2js_server_platform") {
   single_root_scheme = "org-dartlang-sdk"
   single_root_base = "../../"
-  sources = [
-    "org-dartlang-sdk:///sdk/lib/libraries.json",
-  ]
+  libraries_specification_uri = "org-dartlang-sdk:///sdk/lib/libraries.json"
 
   outputs = [
     "$root_out_dir/dart2js_server_platform.dill",
@@ -133,9 +127,7 @@
 compile_platform("compile_dart2js_server_platform_strong") {
   single_root_scheme = "org-dartlang-sdk"
   single_root_base = "../../"
-  sources = [
-    "org-dartlang-sdk:///sdk/lib/libraries.json",
-  ]
+  libraries_specification_uri = "org-dartlang-sdk:///sdk/lib/libraries.json"
 
   outputs = [
     "$root_out_dir/dart2js_server_platform_strong.dill",