Revert "Revert "Always use raster pipeline for radial gradients""

This reverts commit 8b8b2244c3.

Reason for revert: guard landed in g3

Original change's description:
> Revert "Always use raster pipeline for radial gradients"
> 
> This reverts commit 5a5207ae67.
> 
> Reason for revert: suspect this is the reason for Google3 roll failure.
> 
> First color mismatch. Expected ff0006f9, got ff0004fb
> Expected output mismatch apps/cereal/skia_expected/radialGradient.png (3392 pixels)
> 
> 
> Original change's description:
> > Always use raster pipeline for radial gradients
> > 
> > Change-Id: Id4c9ed45c28becf0e25ed9ff1b3380c7ca65aa4b
> > Reviewed-on: https://skia-review.googlesource.com/25363
> > Reviewed-by: Mike Klein <mtklein@chromium.org>
> > Commit-Queue: Florin Malita <fmalita@chromium.org>
> 
> TBR=mtklein@chromium.org,mtklein@google.com,fmalita@chromium.org,reed@google.com
> 
> Change-Id: I382a22f354d3c0a1465bd9c1555f226b0f1abb58
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://skia-review.googlesource.com/25441
> Reviewed-by: Mike Klein <mtklein@google.com>
> Commit-Queue: Mike Klein <mtklein@google.com>

TBR=mtklein@chromium.org,mtklein@google.com,fmalita@chromium.org,reed@google.com

Change-Id: I1a53c98735e5b344d0c2a18800ec94520f328931
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/25660
Reviewed-by: Florin Malita <fmalita@google.com>
Commit-Queue: Florin Malita <fmalita@google.com>

src/shaders/gradients/SkRadialGradient.cpp

@@ -367,8 +367,7 @@ bool SkRadialGradient::onIsRasterPipelineOnly() const {
 #ifdef SK_SUPPORT_LEGACY_RADIAL_GRADIENT
     return false;
 #else
-    // We have a clamp fast path; everything else -> RP.
-    return fTileMode != SkShader::kClamp_TileMode;
+    return true;
 #endif
 }