IDL compiler: Let web_idl.file_io make intermediate directory

web_idl.file_io reads/writes in binary mode so that it produces
the same result on Windows.  Also makes intermediate directories
if necessary.

Bug: 839389
Change-Id: I9743af13acfaa0cefaed6f4b76d6fac28ae3e608
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1980606Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728413}

third_party/blink/renderer/bindings/scripts/bind_gen/codegen_utils.py

@@ -156,5 +156,4 @@ def write_code_node_to_file(code_node, filepath):
 
     format_result = clang_format(rendered_text, filename=filepath)
 
-    with open(filepath, "w") as output_file:
-        output_file.write(format_result.contents)
+    web_idl.file_io.write_to_file_if_changed(filepath, format_result.contents)

third_party/blink/renderer/bindings/scripts/web_idl/__init__.py

@@ -29,6 +29,7 @@ def _setup_sys_path():
 _setup_sys_path()
 
 
+from . import file_io
 from .ast_group import AstGroup
 from .attribute import Attribute
 from .callback_function import CallbackFunction

third_party/blink/renderer/bindings/scripts/web_idl/file_io.py

@@ -10,7 +10,7 @@ def read_pickle_file(filepath):
     """
     Reads the content of the file as a pickled object.
     """
-    with open(filepath, 'r') as file_obj:
+    with open(filepath, 'rb') as file_obj:
         return pickle.load(file_obj)
 
 
@@ -30,7 +30,7 @@ def write_to_file_if_changed(filepath, contents):
     Returns True if the data is written to the file, and False if skipped.
     """
     try:
-        with open(filepath, 'r') as file_obj:
+        with open(filepath, 'rb') as file_obj:
             old_contents = file_obj.read()
     except (OSError, EnvironmentError):
         pass
@@ -38,6 +38,10 @@ def write_to_file_if_changed(filepath, contents):
         if contents == old_contents:
             return False
         os.remove(filepath)
-    with open(filepath, 'w') as file_obj:
+
+    if not os.path.exists(os.path.dirname(filepath)):
+        os.makedirs(os.path.dirname(filepath))
+
+    with open(filepath, 'wb') as file_obj:
         file_obj.write(contents)
     return True