Work on blink GN bindings

Source/core/core.gni

Index: Source/core/core.gni
diff --git a/Source/core/core.gni b/Source/core/core.gni
index c1e51ae1f817c08040b8f09b00dded124f06f634..fd55894b2048b08cc022f30e39b2a12aac7ac6f1 100644
--- a/Source/core/core.gni
+++ b/Source/core/core.gni
@@ -2,32 +2,36 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-# This file is gn GN version of core.gypi. Note that all file lists are
-# relative to the source root unless otherwise noted.
+blink_core_output_dir = "$root_gen_dir/blink/core"
+
+# This file is the GN version of core.gypi. We rebase most paths to be absolute
+# so these lists can be used by BUILD files in different directories without
+# worrying about the base directory.
 _gypi = exec_script(
     "//build/gypi_to_gn.py",
     [ rebase_path("core.gypi"),
-      "--replace=<(SHARED_INTERMEDIATE_DIR)=$root_gen_dir" ],
+      "--replace=<(SHARED_INTERMEDIATE_DIR)=$root_gen_dir",
+      "--replace=<(blink_core_output_dir)=$blink_core_output_dir"],
     "scope",
     [ "core.gypi" ])
 
-# Files for which bindings (.cpp and .h files) will be generated
-core_idl_files = rebase_path(_gypi.core_idl_files, "//")
+# Files for which bindings (.cpp and .h files) will be generated.
+core_idl_files = get_path_info(_gypi.core_idl_files, "abspath")
 
 # 'partial interface', target (right side of) 'implements', and
 # interfaces with static bindings (in bindings/v8/)
-core_dependency_idl_files = rebase_path(_gypi.core_dependency_idl_files, "//")
+core_dependency_idl_files =
+  get_path_info(_gypi.core_dependency_idl_files, "abspath")
 
 # Interfaces that inherit from Event, including Event itself.
-# Files relative to Source/core
-core_event_idl_files = _gypi.core_event_idl_files
+core_event_idl_files = get_path_info(_gypi.core_event_idl_files, "abspath")
 
-webcore_files = rebase_path(_gypi.webcore_files, "//")
-webcore_dom_files = rebase_path(_gypi.webcore_dom_files, "//")
-webcore_html_files = rebase_path(_gypi.webcore_html_files, "//")
-webcore_svg_files = rebase_path(_gypi.webcore_svg_files, "//")
-webcore_testing_idl_files = rebase_path(_gypi.webcore_testing_idl_files, "//")
+webcore_files = get_path_info(_gypi.webcore_files, "abspath")
+webcore_dom_files = get_path_info(_gypi.webcore_dom_files, "abspath")
+webcore_html_files = get_path_info(_gypi.webcore_html_files, "abspath")
+webcore_svg_files = get_path_info(_gypi.webcore_svg_files, "abspath")
+webcore_testing_idl_files = get_path_info(_gypi.webcore_testing_idl_files, "abspath")
 generated_webcore_testing_idl_files =
-  rebase_path(_gypi.generated_webcore_testing_idl_files, "//")
-webcore_testing_files = rebase_path(_gypi.webcore_testing_files, "//")
-core_unittest_files = rebase_path(_gypi.core_unittest_files, "//")
+  get_path_info(_gypi.generated_webcore_testing_idl_files, "abspath")
+webcore_testing_files = get_path_info(_gypi.webcore_testing_files, "abspath")
+core_unittest_files = get_path_info(_gypi.core_unittest_files, "abspath")