electron-build.diff

diff --git a/scripts/patch.py b/scripts/patch.py
index 62dd248b..e4b7da1f 100755
--- a/scripts/patch.py
+++ b/scripts/patch.py
@@ -29,6 +29,10 @@ def parse_args():
                         type=boolean_string, nargs='?',
                         default=False, const=True,
                         help="dry run")
+    parser.add_argument('--remove',
+                        type=boolean_string, nargs='?',
+                        default=True, const=True,
+                        help="remove old files when exporting patches")
 
     parser.add_argument('-f', '--apply-ffmpeg-patches',
                         type=boolean_string, nargs='?',
@@ -144,7 +148,7 @@ def get_config_targets(config, patch_source_project_root=PROJECT_ROOT_DIR):
     return json.loads(config_data)
 
 
-def export_patches(config, dry_run,
+def export_patches(config, dry_run, remove_old_patches,
                    patch_source_project_root=PROJECT_ROOT_DIR,
                    patch_target_project_root=PROJECT_ROOT_DIR):
     for target in get_config_targets(
@@ -164,6 +168,7 @@ def export_patches(config, dry_run,
                            out_dir=out_dir,
                            patch_range=None,
                            dry_run=dry_run,
+                           remove_old_patches=remove_old_patches,
                            grep="Patch-Dir: {}".format(out_dir),
                            ref="refs/{}/upstream-head".format(patch_dir))
 
@@ -227,7 +232,7 @@ def get_target_repo_and_directory(repo_path, is_snapshot):
     # Let's exclude "src/" from a path,
     # e.g. "src/third_party/ffmpeg" -> "third_party/ffmpeg".
     directory, top_level_dir = exclude_top_level_dir(repo_path)
-    assert(top_level_dir == src_repo)
+    assert (top_level_dir == src_repo)
 
     return src_repo, directory
 
@@ -250,7 +255,9 @@ def main():
     configs = get_configs_list(script_args.apply_ffmpeg_patches, is_snapshot)
     for config in configs:
         if script_args.export:
-            export_patches(config, dry_run=script_args.dry_run)
+            export_patches(config,
+                           dry_run=script_args.dry_run,
+                           remove_old_patches=script_args.remove),
         else:
             apply_patches(config, is_snapshot)
 

electron.diff

diff --git a/script/lib/git.py b/script/lib/git.py
index 3153c6ad4..178d736df 100644
--- a/script/lib/git.py
+++ b/script/lib/git.py
@@ -231,7 +231,8 @@ def remove_patch_location(patch):
 
 def export_patches(repo, out_dir,
                    patch_range=None, ref=UPSTREAM_HEAD,
-                   dry_run=False, grep=None):
+                   dry_run=False, remove_old_patches=True,
+                   grep=None):
   if not os.path.exists(repo):
     sys.stderr.write(
       "Skipping patches in {} because it does not exist.\n".format(repo)
@@ -275,9 +276,10 @@ def export_patches(repo, out_dir,
   else:
     # Remove old patches so that deleted commits are correctly reflected in the
     # patch files (as a removed file)
-    for p in os.listdir(out_dir):
-      if p.endswith('.patch'):
-        os.remove(posixpath.join(out_dir, p))
+    if remove_old_patches:
+      for p in os.listdir(out_dir):
+        if p.endswith('.patch'):
+          os.remove(posixpath.join(out_dir, p))
     with io.open(
       posixpath.join(out_dir, '.patches'),
       'w',