GitLab

|top_toolbar_height_in_viewport_coords_| and |background_color_| are
common attributes for both OutOfProcessInstance and PdfViewWebPlugin.
This CL moves them to PdfViewPluginBase, and provides accessors and
mutators for them.

Bug: 1140629
Change-Id: I1df7ea3d8e89e5d3ab3ff00ba5bfe40170ac2c26
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2599704
Commit-Queue: Hui Yingst <nigi@chromium.org>
Reviewed-by: K. Moon <kmoon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#839159}