Register some flattenable factories.

Now, SkComposeShaders, SkDiscreteMapper, SkCosineMapper,
Line2DPathEffect, and SkTransparentShader can be flattened
and unflattened. This makes more of our samples work when
using a pipe.

Review URL: https://codereview.appspot.com/6338064

git-svn-id: http://skia.googlecode.com/svn/trunk@4334 2bbb7eff-a529-9590-31e7-b0007b416f81

samplecode/SampleAll.cpp

@@ -250,6 +250,8 @@ private:
     typedef Sk2DPathEffect INHERITED;
 };
 
+SK_DEFINE_FLATTENABLE_REGISTRAR(Line2DPathEffect)
+
 static void r9(SkLayerRasterizer* rast, SkPaint& p) {
     rast->addLayer(p);
     

src/core/SkComposeShader.cpp

@@ -165,3 +165,5 @@ void SkComposeShader::shadeSpan(int x, int y, SkPMColor result[], int count) {
     }
 }
 
+SK_DEFINE_FLATTENABLE_REGISTRAR(SkComposeShader)
+

src/effects/SkTransparentShader.cpp

@@ -125,3 +125,5 @@ void SkTransparentShader::shadeSpan16(int x, int y, uint16_t span[], int count)
         memcpy(span, src, count << 1);
     }
 }
+
+SK_DEFINE_FLATTENABLE_REGISTRAR(SkTransparentShader)

src/utils/SkUnitMappers.cpp

@@ -57,3 +57,5 @@ uint16_t SkCosineMapper::mapUnit16(uint16_t input)
 SkCosineMapper::SkCosineMapper(SkFlattenableReadBuffer& rb)
     : SkUnitMapper(rb) {}
 
+SK_DEFINE_FLATTENABLE_REGISTRAR(SkDiscreteMapper)
+SK_DEFINE_FLATTENABLE_REGISTRAR(SkCosineMapper)