Reorganize Blink IDL build, delete obsolete GYP files.

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

 # Copyright 2014 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("//third_party/WebKit/Source/bindings/core/core.gni")
-import("//third_party/WebKit/Source/bindings/core/idl.gni")
 import("//third_party/WebKit/Source/bindings/scripts/scripts.gni")
 import("//third_party/WebKit/Source/core/core_idl_files.gni")
 
 visibility = [ "//third_party/WebKit/*" ]
 
 # Static IDL files / Generated IDL files
 #
 # In GYP, paths needed to be passed separately for static and generated files, as
 # static files are listed in a temporary file (b/c too long for command line),
 # but generated files must be passed at the command line, as their paths are
@@ skipping 26 matching lines @@
 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"
   output_dir = blink_core_output_dir
   deps = [
     ":core_global_objects",
   ]
 }