Revert "Remove some blur tests on google3 until the flag is removed."

This reverts commit a0020f987e73630592a3e5fb3117830a5b2017a4.

Reason for revert: don't need this

Original change's description:
> Remove some blur tests on google3 until the flag is removed.
> 
> Change 52771 is causing google3 to fail because some tests changed
> and were not guarded by a legacy flag.
> 
> Change-Id: I7ad5b83315bba98744f89860dd03fffc66a88248
> Reviewed-on: https://skia-review.googlesource.com/60740
> Commit-Queue: Herb Derby <herb@google.com>
> Reviewed-by: Mike Klein <mtklein@chromium.org>

TBR=mtklein@chromium.org,mtklein@google.com,herb@google.com

Change-Id: Ib4f102442f6b11c276e020406808bd88344657a5
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/61321
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
diff --git a/tests/ImageFilterTest.cpp b/tests/ImageFilterTest.cpp
index ac847ce..c39cc2e 100644
--- a/tests/ImageFilterTest.cpp
+++ b/tests/ImageFilterTest.cpp
@@ -836,8 +836,6 @@
     }
 }
 
-#if !defined(SK_SUPPORT_LEGACY_BLUR_IMAGE)
-
 static sk_sp<SkImageFilter> make_blur(sk_sp<SkImageFilter> input) {
     return SkBlurImageFilter::Make(SK_Scalar1, SK_Scalar1, std::move(input));
 }
@@ -955,8 +953,6 @@
     REPORTER_ASSERT(reporter, boundsDst == expectedBounds);
 }
 
-#endif
-
 DEF_TEST(ImageFilterUnionBounds, reporter) {
     sk_sp<SkImageFilter> offset(SkOffsetImageFilter::Make(50, 0, nullptr));
     // Regardless of which order they appear in, the image filter bounds should