The media modal main background should be white

[afercia]

In the media modal, the background of the content (the left part in the screenshots) used to be white:

now is gray:

Introduced in [41833].

When working on the admin stylesheets, low qualified selectors like .attachment-media-view tend to apply to several screens and should always be double checked.

[chetan200891]

Created patch to make media modal main background white.

[chetan200891]

Created patch 43088.diff to make media modal background white. It looks good to me!

[afercia]

@chetan200891 thanks! You beat me by 9 seconds, lol.

However, the other backgrounds should stay gray (they're the "No image selected" placeholder in the widgets, see #42101).

[chetan200891]

@afercia Hahaha.. Yes.. But your patch is more better!

[afercia]

43088.3.diff​ tries a simpler approach to keep the gray background for all the widget placeholders and restore the white background in the media modal. Also, removes a trailing space.

[dd32]

Bumping to 4.9.3 due to 4.9.2s release

[SergeyBiryukov]

In 42572:

Media: Restore white background of the content area in media modal.

Props afercia, chetan200891.
Fixes #43088.

[SergeyBiryukov]

In 42573:

Media: Restore white background of the content area in media modal.

Props afercia, chetan200891.
Merges [42572] to the 4.9 branch.
Fixes #43088.