ci compress linux debug symbols

Start compressing the extracted debug symbols. The current size of the
.debug file is over 2 GB.

#13315

.circleci/config.yml

@@ -283,7 +283,7 @@ step-maybe-electron-dist-strip: &step-maybe-electron-dist-strip
         mkdir out/Default/debug
         # Generate electron.debug. Required to do it from there in order to maintain debug references.
         cd out/Default/debug
-        ../../../electron/script/copy-debug-symbols.py --target-cpu="$TARGET_ARCH"
+        ../../../electron/script/copy-debug-symbols.py --target-cpu="$TARGET_ARCH" --compress
         ../../../electron/script/strip-binaries.py --target-cpu="$TARGET_ARCH"
         ../../../electron/script/copy-debug-symbols.py --target-cpu="$TARGET_ARCH" --add-debug-link
       fi

script/copy-debug-symbols.py

@@ -8,18 +8,21 @@
 from lib.util import execute, get_out_dir
 
 # It has to be done before stripping the binaries.
-def copy_debug_from_binaries(directory, target_cpu):
+def copy_debug_from_binaries(directory, target_cpu, compress):
   for binary in LINUX_BINARIES_TO_STRIP:
     binary_path = os.path.join(directory, binary)
     if os.path.isfile(binary_path):
-      copy_debug_from_binary(binary_path, target_cpu)
+      copy_debug_from_binary(binary_path, target_cpu, compress)
 
-def copy_debug_from_binary(binary_path, target_cpu):
+def copy_debug_from_binary(binary_path, target_cpu, compress):
   objcopy = get_objcopy_path(target_cpu)
   if not objcopy:
     return
   debug_name = get_debug_name(binary_path)
-  cmd = [objcopy, '--only-keep-debug', binary_path, debug_name]
+  cmd = [objcopy, '--only-keep-debug']
+  if compress:
+      cmd.extend(['--compress-debug-sections'])
+  cmd.extend([binary_path, debug_name])
   execute(cmd)
   return debug_name
 
@@ -57,9 +60,9 @@ def main():
       add_debug_link_into_binaries(args.directory, args.target_cpu)
   else:
     if args.file:
-      copy_debug_from_binary(args.file, args.target_cpu)
+      copy_debug_from_binary(args.file, args.target_cpu, args.compress)
     else:
-      copy_debug_from_binaries(args.directory, args.target_cpu)
+      copy_debug_from_binaries(args.directory, args.target_cpu, args.compress)
 
 def parse_args():
   parser = argparse.ArgumentParser(description='Copy debug from binaries')
@@ -81,6 +84,10 @@ def parse_args():
                       action='store_true',
                       required=False,
                       help='Path to a specific file to add the debug link')
+  parser.add_argument('--compress',
+                      action='store_true',
+                      required=False,
+                      help='Compress the debug symbols')
 
   return parser.parse_args()