Bindings: generate_global_constructors template needs one more parameter.

Add "basename" parameter to template("generate_global_constructors"),
and generate snake_case IDL files and C++ header files.

This is a preparation of the Great Blink mv. At this momnet, we only
have lists of global scope interface names in *.gn. After the great mv,
it's difficult to produce generated IDL list and C++ header list from
the interface names in *.gn. So we need to introduce additional
snake_cased interface list.

Bug: 578345
Change-Id: Ia7f861e43d9b622926adde0280e4297c71bcc750
Reviewed-on: https://chromium-review.googlesource.com/672225Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#502817}

third_party/WebKit/Source/bindings/core/BUILD.gn

@@ -32,7 +32,8 @@ generate_global_constructors("core_global_constructors_idls") {
   sources = core_idl_files + core_idl_with_modules_dependency_files
   global_objects_file = "$bindings_core_output_dir/GlobalObjectsCore.pickle"
   interfaces = core_global_constructors_original_interfaces
-  component = "Core"
+  basenames = core_global_constructors_original_interface_basenames
+  component = "core"
   output_dir = blink_core_output_dir
   deps = [
     ":core_global_objects",

third_party/WebKit/Source/bindings/modules/BUILD.gn

@@ -157,7 +157,8 @@ generate_global_constructors("modules_core_global_constructors_idls") {
   global_objects_file =
       "$bindings_modules_output_dir/GlobalObjectsModules.pickle"
   interfaces = modules_core_global_constructors_original_interfaces
-  component = "Core"
+  basenames = modules_core_global_constructors_original_interface_basenames
+  component = "core"
   output_dir = blink_modules_output_dir
   deps = [
     ":modules_global_objects",
@@ -169,7 +170,8 @@ generate_global_constructors("modules_global_constructors_idls") {
   global_objects_file =
       "$bindings_modules_output_dir/GlobalObjectsModules.pickle"
   interfaces = modules_global_constructors_original_interfaces
-  component = "Modules"
+  basenames = modules_global_constructors_original_interface_basenames
+  component = "modules"
   output_dir = blink_modules_output_dir
   deps = [
     ":modules_global_objects",

third_party/WebKit/Source/bindings/scripts/scripts.gni

@@ -462,16 +462,22 @@ template("generate_global_constructors") {
     output_dir = invoker.output_dir
     component = invoker.component
 
-    # generate outputs from invoker.interfaces.
+    # generate outputs from invoker.interfaces and invoker.basenames.
     output_idl_files = []
     output_header_files = []
+
+    # Need a variable due to a GN sytax restriction. We can't do "invoker.basenames[i]".
+    basename_list = invoker.basenames
+    i = 0
     foreach(interface, invoker.interfaces) {
+      basename = basename_list[i]
       args += [ interface ]
-      output_idl_file = "$output_dir/${interface}${component}Constructors.idl"
+      output_idl_file = "$output_dir/${basename}_${component}_constructors.idl"
       args += [ rebase_path(output_idl_file, root_build_dir) ]
       output_idl_files += [ output_idl_file ]
       output_header_files +=
-          [ "$output_dir/${interface}${component}Constructors.h" ]
+          [ "$output_dir/${basename}_${component}_constructors.h" ]
+      i += 1
     }
 
     outputs = output_idl_files + output_header_files

third_party/WebKit/Source/core/core_idl_files.gni

@@ -17,13 +17,20 @@ core_global_constructors_original_interfaces = [
   "DedicatedWorkerGlobalScope",
 ]
 
+# The size and the order in the following list must match to the previous one.
+core_global_constructors_original_interface_basenames = [
+  "window",
+  "shared_worker_global_scope",
+  "dedicated_worker_global_scope",
+]
+
 # The interfaces aren't technically files, but we can treat them as file names
 # to get process_file_template to generate lists of IDL files corresponding
 # to each interface.
 core_global_constructors_generated_idl_files =
     process_file_template(
-        core_global_constructors_original_interfaces,
-        [ "$blink_core_output_dir/{{source_name_part}}CoreConstructors.idl" ])
+        core_global_constructors_original_interface_basenames,
+        [ "$blink_core_output_dir/{{source_name_part}}_core_constructors.idl" ])
 
 core_idl_files =
     get_path_info([

third_party/WebKit/Source/modules/modules_idl_files.gni

@@ -17,6 +17,14 @@ modules_core_global_constructors_original_interfaces = [
   "ServiceWorkerGlobalScope",
 ]
 
+# The size and the order in the following list must match to the previous one.
+modules_core_global_constructors_original_interface_basenames = [
+  "audio_worklet_global_scope",
+  "compositor_worker_global_scope",
+  "paint_worklet_global_scope",
+  "service_worker_global_scope",
+]
+
 modules_global_constructors_original_interfaces = [
   "AudioWorkletGlobalScope",
   "CompositorWorkerGlobalScope",
@@ -27,15 +35,26 @@ modules_global_constructors_original_interfaces = [
   "Window",
 ]
 
+# The size and the order in the following list must match to the previous one.
+modules_global_constructors_original_interface_basenames = [
+  "audio_worklet_global_scope",
+  "compositor_worker_global_scope",
+  "dedicated_worker_global_scope",
+  "paint_worklet_global_scope",
+  "service_worker_global_scope",
+  "shared_worker_global_scope",
+  "window",
+]
+
 # The interfaces aren't technically files, but we can treat them as file names
 # to get process_file_template to generate lists of IDL files corresponding
 # to each interface.
 modules_core_global_constructors_generated_idl_files = process_file_template(
-        modules_core_global_constructors_original_interfaces,
-        [ "$blink_modules_output_dir/{{source_name_part}}CoreConstructors.idl" ])
+        modules_core_global_constructors_original_interface_basenames,
+        [ "$blink_modules_output_dir/{{source_name_part}}_core_constructors.idl" ])
 modules_global_constructors_generated_idl_files = process_file_template(
-        modules_global_constructors_original_interfaces,
-        [ "$blink_modules_output_dir/{{source_name_part}}ModulesConstructors.idl" ])
+        modules_global_constructors_original_interface_basenames,
+        [ "$blink_modules_output_dir/{{source_name_part}}_modules_constructors.idl" ])
 
 modules_idl_files =
     get_path_info([