Get gradient information for gpu effect directly from SkGradientShader instead of calling asAGradie…

src/effects/gradients/SkGradientShaderPriv.h

Index: src/effects/gradients/SkGradientShaderPriv.h
diff --git a/src/effects/gradients/SkGradientShaderPriv.h b/src/effects/gradients/SkGradientShaderPriv.h
index 1d0f008917d42d974c393d3fb4c31dbd580d8572..b81915bc71540bb5a14535285f85ad8a9dec0c6a 100644
--- a/src/effects/gradients/SkGradientShaderPriv.h
+++ b/src/effects/gradients/SkGradientShaderPriv.h
@@ -98,6 +98,19 @@ public:
         uint32_t            fFlags;
     };
 
+    // Specialized Descriptor used for setting up gpu gradient effect
+    struct DescriptorGpu {

[bsalomon, 2014/04/17 19:23:34]

How about we move the logic about whether it is a 2 or 3 color special case into
this new function so we don't have to return a t value and all the colors all
the time.

enum GpuColorType { ... } // moved from GrGradientEffect to SkGradientShader
struct GpuGradientDesc {
    GpuColorType fType;
    SkColor      fColors[3]; // only valid when fType is kTwo or kThree
    bool         fPremulAfterInterp;
    TileMode     fTileMode;
}

+        DescriptorGpu() {
+            sk_bzero(this, sizeof(*this));
+        }
+
+        SkColor*            fColors;
+        SkScalar            fMidPos;
+        int                 fCount;
+        SkShader::TileMode  fTileMode;
+        uint32_t            fFlags;
+    };
+
 public:
     SkGradientShaderBase(const Descriptor& desc);
     virtual ~SkGradientShaderBase();
@@ -185,6 +198,8 @@ public:
         kDitherStride16 = kCache16Count,
     };
 
+    void getGradientDescriptorGpu(DescriptorGpu* desc) const;
+
 protected:
     SkGradientShaderBase(SkReadBuffer& );
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;