Introduces new SingleTextureEffect base class for GrCustomStage objects.
This class tracks the texture that the object uses. A future commit will get rid of the
GrTexture pointer currenty stored in the GrDrawState, allowing us to have CustomStages
*without* textures.

Requires gyp change on next roll.

http://codereview.appspot.com/6306097/



git-svn-id: http://skia.googlecode.com/svn/trunk@4576 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/effects/GrConvolutionEffect.h b/src/gpu/effects/GrConvolutionEffect.h
index fd6883b..58cad83 100644
--- a/src/gpu/effects/GrConvolutionEffect.h
+++ b/src/gpu/effects/GrConvolutionEffect.h
@@ -21,7 +21,8 @@
 
 public:
 
-    GrConvolutionEffect(Direction, int halfWidth, const float* kernel = NULL);
+    GrConvolutionEffect(GrTexture*, Direction,
+                        int halfWidth, const float* kernel = NULL);
     virtual ~GrConvolutionEffect();
 
     void setKernel(const float* kernel) {