Twenty Fifteen: merge Header & Sidebar text color controls

[celloexpressions]

We only have one control for the header/sidebar background color and header/sidebar background image, so why do we have separate controls for different parts of the text's colors? In addition to being confusing, we should be able to simplify the interaction with colorschemes a bit, as well as simplifying the user experience by considering "Decisions, not Options".

This should also make it faster/easier to Customize the theme by having one less option, without removing a particularly useful customization option. Patch should clean up all of the related code, although I may have missed a couple things.

[celloexpressions]

Remove header text color control, and use the sidebar text color for those elements.

[iamtakashi]

I like this approach and we don't need to worry about #29980 but three things.

• We need to disable "Text Color" option in Appearance -> Header since it won't do anything.
• Let's change the label for the control in Customizer to "Header & Sidebar Text Color".
• We need to cleanup the color-scheme-control.js also.

[celloexpressions]

Appearance -> Header is being deprecated - it'll only be accessible by users with no js, on IE7 or in IE8 or IE9 on multisite with domain mapping (those are the situations when the Customizer isn't available). Users will otherwise be redirected to the appropriate controls in the Customizer So I actually think we shouldn't consider it at all in Twenty Fifteen, although I added it to that file for now.

New patch addresses the other notes. Noting that we need to use the custom sidebar_textcolor control for this, since the core control is tied to the option to hide the header text, and this color applies to more than that.

[iamtakashi]

Replying to celloexpressions:

Appearance -> Header is being deprecated - it'll only be accessible by users with no js, on IE7 or in IE8 or IE9 on multisite with domain mapping (those are the situations when the Customizer isn't available). Users will otherwise be redirected to the appropriate controls in the Customizer So I actually think we shouldn't consider it at all in Twenty Fifteen, although I added it to that file for now.

OK, that's good to know. In that case, I think hiding it with CSS is fine too.

New patch addresses the other notes. Noting that we need to use the custom sidebar_textcolor control for this, since the core control is tied to the option to hide the header text, and this color applies to more than that.

Yes. That makes sense.

I've tested 30164.2.diff and I haven't seen anything weird other than the known issues — the escaped label #29572 and the default background color #30125, #30031.

When this is committed, we can close #29980.

[iandstewart]

Looks like this patch is out of sync for me and I _think_ for iamtakashi as well.

[celloexpressions]

Hmm, I can't apply it anymore either, and it seems to be rejecting applying to any files (and can't find the right paths). If someone has time to do a manual refresh, that's probably needed.

[iamtakashi]

Updated patch

[iandstewart]

In 30230:

Twenty Fifteen: Simplify the header, sidebar, background controls and make customization faster for users to do. This has the added benefit of fixing our bug where hidden header text wasn't being updated on color scheme switch. Nice.

Props celloexpressions, iamtakashi, fixes #30164 and #29980.