Fix some guards for USE(THEME_ADWAITA)

https://bugs.webkit.org/show_bug.cgi?id=261003

Reviewed by Michael Catanzaro.

Miscellaneous fixes to make `USE_THEME_ADWAITA` work more cross
platform.

* Source/WTF/wtf/PlatformUse.h:
* Source/WebCore/Modules/mediacontrols/MediaControlsHost.cpp:
(WebCore::MediaControlsHost::layoutTraitsClassName const):
* Source/WebCore/rendering/RenderThemeAdwaita.cpp:
(WebCore::RenderThemeAdwaita::systemColor const):

Canonical link: https://commits.webkit.org/267554@main

Source/WTF/wtf/PlatformUse.h

@@ -263,7 +263,7 @@
 #define USE_CFNETWORK_CONTENT_ENCODING_SNIFFING_OVERRIDE 1
 #endif
 
-#if PLATFORM(MAC) || PLATFORM(WPE) || PLATFORM(GTK) || PLATFORM(WIN)
+#if PLATFORM(MAC) || USE(THEME_ADWAITA)
 /* FIXME: This really needs a descriptive name, this "new theme" was added in 2008. */
 #define USE_NEW_THEME 1
 #endif

Source/WebCore/Modules/mediacontrols/MediaControlsHost.cpp

@@ -122,7 +122,7 @@ String MediaControlsHost::layoutTraitsClassName() const
     return "VisionLayoutTraits"_s;
 #elif PLATFORM(WATCHOS)
     return "WatchOSLayoutTraits"_s;
-#elif PLATFORM(GTK) || PLATFORM(WPE) || PLATFORM(WIN)
+#elif USE(THEME_ADWAITA)
     return "AdwaitaLayoutTraits"_s;
 #else
     ASSERT_NOT_REACHED();

Source/WebCore/rendering/RenderThemeAdwaita.cpp

@@ -272,7 +272,9 @@ Color RenderThemeAdwaita::systemColor(CSSValueID cssValueID, OptionSet<StyleColo
 
     case CSSValueCanvas:
     case CSSValueField:
+#if HAVE(OS_DARK_MODE_SUPPORT)
     case CSSValueWebkitControlBackground:
+#endif
         return useDarkAppearance ? textFieldBackgroundColorDark : textFieldBackgroundColorLight;
 
     case CSSValueWindow: