That is generally wrong on macOS [which by default uses cmd + C]. Furthermore, on macOS, the hotkey is user configurable to be whatever they want.

https://cs.chromium.org/search/?q=VKEY_C+file:views&sq=package:chromium&type=cs

e.g.
"""
bool Label::AcceleratorPressed(const ui::Accelerator& accelerator) {
  // Allow the "Copy" action from the Chrome menu to be invoked. E.g., if a user
  // selects a Label on a web modal dialog. "Select All" doesn't appear in the
  // Chrome menu so isn't handled here.
  if (accelerator.key_code() == ui::VKEY_C && accelerator.IsCtrlDown()) {
    CopyToClipboard();
    return true;
  }
  return false;
}
"""