void SkColorFilter::onAppendStages(...)

SkColorFilter::onAppendStages() can't actually fail today.
Let's enforce that.  This means the fallback is now used
only for color filters that have not implemented onAppendStages().

Change-Id: Ica3939685694f6186727766b54914b9ba05ca68c
Reviewed-on: https://skia-review.googlesource.com/16231
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
diff --git a/include/core/SkColorFilter.h b/include/core/SkColorFilter.h
index 1637549..2e36627 100644
--- a/include/core/SkColorFilter.h
+++ b/include/core/SkColorFilter.h
@@ -185,7 +185,7 @@
         return false;
     }
 
-    virtual bool onAppendStages(SkRasterPipeline*, SkColorSpace*, SkArenaAlloc*,
+    virtual void onAppendStages(SkRasterPipeline*, SkColorSpace*, SkArenaAlloc*,
                                 bool shaderIsOpaque) const;