DevTools: allow styling the page number element when printing over the protocol.

Bug: none
Change-Id: I13e6afbd86a7c6bcdedbf0645183194b9de7cfb4
Reviewed-on: https://chromium-review.googlesource.com/809759
Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Jianzhou Feng <jzfeng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523966}
PrintRenderFrameHelper::PrintRenderFrameHelper(
    content::RenderFrame* render_frame,
    std::unique_ptr<Delegate> delegate)
    : content::RenderFrameObserver(render_frame),
      content::RenderFrameObserverTracker<PrintRenderFrameHelper>(render_frame),
      reset_prep_frame_view_(false),
      is_print_ready_metafile_sent_(false),
      ignore_css_margins_(false),
      is_printing_enabled_(true),
      notify_browser_of_print_failure_(true),
      print_for_preview_(false),
      delegate_(std::move(delegate)),
      print_node_in_progress_(false),
      is_loading_(false),
      is_scripted_preview_delayed_(false),
      ipc_nesting_level_(0),
      render_frame_gone_(false),
      weak_ptr_factory_(this) {
  if (!delegate_->IsPrintPreviewEnabled())
    DisablePreview();
}

PrintRenderFrameHelper::PrintRenderFrameHelper(
    content::RenderFrame* render_frame,
    std::unique_ptr<Delegate> delegate)
    : content::RenderFrameObserver(render_frame),
      content::RenderFrameObserverTracker<PrintRenderFrameHelper>(render_frame),
      reset_prep_frame_view_(false),
      is_print_ready_metafile_sent_(false),
      ignore_css_margins_(false),
      is_printing_enabled_(true),
      notify_browser_of_print_failure_(true),
      print_for_preview_(false),
      delegate_(std::move(delegate)),
      print_node_in_progress_(false),
      is_loading_(false),
      is_scripted_preview_delayed_(false),
      ipc_nesting_level_(0),
      render_frame_gone_(false),
      weak_ptr_factory_(this) {
  if (!delegate_->IsPrintPreviewEnabled())
    DisablePreview();
}
