Partial revert of "Enable SkiaRenderer by default on Linux"

This reverts commit b344f6f2, while
keeping the buildbot changes which are safe to keep.

Bug: 967716
Change-Id: Ie983fb911aaa80f90536df1fd5c50dfc66927692
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1951146Reviewed-by: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/master@{#721559}

components/viz/common/features.cc

@@ -22,13 +22,8 @@ const base::Feature kUseSkiaForGLReadback{"UseSkiaForGLReadback",
                                           base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Use the SkiaRenderer.
-#if defined(OS_LINUX) && !(defined(OS_CHROMEOS) || defined(IS_CHROMECAST))
-const base::Feature kUseSkiaRenderer{"UseSkiaRenderer",
-                                     base::FEATURE_ENABLED_BY_DEFAULT};
-#else
 const base::Feature kUseSkiaRenderer{"UseSkiaRenderer",
                                      base::FEATURE_DISABLED_BY_DEFAULT};
-#endif
 
 // Use the SkiaRenderer to record SkPicture.
 const base::Feature kRecordSkPicture{"RecordSkPicture",