Erode and dilate image filter effects, CPU and GPU implementations.

Review URL:  http://codereview.appspot.com/5656067/



git-svn-id: http://skia.googlecode.com/svn/trunk@3310 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGpuGL.cpp b/src/gpu/gl/GrGpuGL.cpp
index bee2017..69880e5 100644
--- a/src/gpu/gl/GrGpuGL.cpp
+++ b/src/gpu/gl/GrGpuGL.cpp
@@ -445,7 +445,7 @@
                                                   -GR_ScalarMax,
                                                   true);
         *fHWDrawState.sampler(s)->matrix() = GrMatrix::InvalidMatrix();
-        fHWDrawState.sampler(s)->setConvolutionParams(0, NULL, NULL);
+        fHWDrawState.sampler(s)->setConvolutionParams(0, NULL);
     }
 
     fHWBounds.fScissorRect.invalidate();
@@ -1935,6 +1935,8 @@
             return GR_GL_LINEAR;
         case GrSamplerState::kNearest_Filter:
         case GrSamplerState::kConvolution_Filter:
+        case GrSamplerState::kErode_Filter:
+        case GrSamplerState::kDilate_Filter:
             return GR_GL_NEAREST;
         default:
             GrAssert(!"Unknown filter type");