have shaders that need seed_shader call it themselves

This ought to make compose shader and our sprite blitter a bit more
efficient.  Compose shader can simply re-seed instead of saving the
xy values off to a buffer.  The sprite blitter doesn't need xy at all.

Change-Id: Ib4b3509288810f74a4c8e2978ce2ca14d8644980
Reviewed-on: https://skia-review.googlesource.com/18405
Reviewed-by: Herb Derby <herb@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/shaders/SkImageShader.cpp b/src/shaders/SkImageShader.cpp
index d46d2558e8..bdbd382638 100644
--- a/src/shaders/SkImageShader.cpp
+++ b/src/shaders/SkImageShader.cpp
@@ -258,6 +258,7 @@ bool SkImageShader::onAppendStages(SkRasterPipeline* p, SkColorSpace* dstCS, SkA
         }
     }
 
+    p->append(SkRasterPipeline::seed_shader);
 
     struct MiscCtx {
         std::unique_ptr<SkBitmapController::State> state;