Remove flag (thus enabling a Skia bug fix) and rebaseline an affected unit test

Bug: skia:7765
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel
Change-Id: I2147e4450f134473b059399b67d58633d277e5bd
Reviewed-on: https://chromium-review.googlesource.com/1044787Reviewed-by: enne <enne@chromium.org>
Commit-Queue: Robert Phillips <robertphillips@google.com>
Cr-Commit-Position: refs/heads/master@{#557172}

skia/config/SkUserConfig.h

@@ -203,13 +203,6 @@ SK_API void SkDebugf_FileLine(const char* file, int line, bool fatal,
 #define SK_SUPPORT_LEGACY_TILED_BITMAPS
 #endif
 
-// cc_unittests LayerTreeHostFiltersPixelTest.BackgroundFilterBlurOutsets fail
-// with the Skia blur imagefilter bug-fix. They need to be updated at the
-// same time this flag is removed.
-#ifndef SK_IGNORE_BLUR_IMAGE_FILTER_FIX
-#define SK_IGNORE_BLUR_IMAGE_FILTER_FIX
-#endif
-
 // remove after rebaselining svg layout tests
 #ifndef SK_SUPPORT_LEGACY_SVG_ARC_TO
 #define SK_SUPPORT_LEGACY_SVG_ARC_TO