Remove legacy gpu blur util code

TBR:michaelludwig@google.com

Bug: skia:10818
Change-Id: I1326aa017c0ed000efee1b9e0372a12976ba09eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/324895
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
Auto-Submit: Brian Salomon <bsalomon@google.com>

Author: bsalomon

gn/core.gni

@@ -243,7 +243,6 @@ skia_core_sources = [
   "$_src/core/SkLRUCache.h",
   "$_src/core/SkLatticeIter.cpp",
   "$_src/core/SkLatticeIter.h",
-  "$_src/core/SkLegacyGpuBlurUtils.cpp",
   "$_src/core/SkLineClipper.cpp",
   "$_src/core/SkLocalMatrixImageFilter.cpp",
   "$_src/core/SkLocalMatrixImageFilter.h",

src/core/SkGpuBlurUtils.cpp

@@ -386,18 +386,6 @@ static std::unique_ptr<GrRenderTargetContext> two_pass_gaussian(GrRecordingConte
 
 namespace SkGpuBlurUtils {
 
-std::unique_ptr<GrRenderTargetContext> LegacyGaussianBlur(GrRecordingContext* context,
-                                                          GrSurfaceProxyView srcView,
-                                                          GrColorType srcColorType,
-                                                          SkAlphaType srcAlphaType,
-                                                          sk_sp<SkColorSpace> colorSpace,
-                                                          const SkIRect& dstBounds,
-                                                          const SkIRect& srcBounds,
-                                                          float sigmaX,
-                                                          float sigmaY,
-                                                          SkTileMode mode,
-                                                          SkBackingFit fit);
-
 std::unique_ptr<GrRenderTargetContext> GaussianBlur(GrRecordingContext* context,
                                                     GrSurfaceProxyView srcView,
                                                     GrColorType srcColorType,
@@ -409,10 +397,6 @@ std::unique_ptr<GrRenderTargetContext> GaussianBlur(GrRecordingContext* context,
                                                     float sigmaY,
                                                     SkTileMode mode,
                                                     SkBackingFit fit) {
-#ifdef SK_USE_LEGACY_GPU_BLUR
-    return LegacyGaussianBlur(context, srcView, srcColorType, srcAlphaType, std::move(colorSpace),
-                              dstBounds, srcBounds, sigmaX, sigmaY, mode, fit);
-#endif
     SkASSERT(context);
     TRACE_EVENT2("skia.gpu", "GaussianBlur", "sigmaX", sigmaX, "sigmaY", sigmaY);